Radiolabeled prostate specific membrane antigen inhibitors

ABSTRACT

Compounds according to Formula I and Formula II are potent inhibitors of PSMA activity: 
     
       
         
         
             
             
         
       
     
     Pharmaceutical compositions may include a complex of a radionuclide and a compound of Formula I or Formula II.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.13/566,849, filed Aug. 3, 2012, which in turn claims the benefit of U.S.Provisional Application Ser. No. 61/515,674, filed Aug. 5, 2011, theentire contents of which are incorporated by reference herein in theirentirety.

TECHNICAL FIELD

The present technology generally relates to the field ofradiopharmaceuticals and their use in nuclear medicine as tracers,imaging agents and for the treatment of various disease states.

BACKGROUND

It is well known that tumors may express unique proteins associated withtheir malignant phenotype or may over-express normal constituentproteins in greater number than normal cells. The expression of distinctproteins on the surface of tumor cells offers the opportunity todiagnose and characterize disease by probing the phenotypic identity andbiochemical composition and activity of the tumor. Radioactive moleculesthat selectively bind to specific tumor cell surface proteins provide anattractive route for imaging and treating tumors under non-invasiveconditions. In particular, the present inventors have found thatradiolabeled ligands to the prostate-specific membrane antigen (PSMA)protein, often over expressed on many cancer cells provide an attractiveroute for non-invasive imaging and selective targeting of cancer cells.

At least 1 million men suffer from prostate cancer and it's estimatedthat the disease will strike one in six U.S. men between the ages of 60and 80. There are more than 300,000 new cases of prostate cancerdiagnosed each year. Prostate cancer will affect one in six men in theUnited States, and the mortality from the disease is second only to lungcancer. An estimated $2 billion is currently spent worldwide onsurgical, radiation, drug therapy and minimally invasive treatments, $1billion of the spending in the U.S. There is presently no effectivetherapy for relapsing, metastatic, androgen-independent prostate cancer.New agents that will enable rapid visualization of prostate cancer andspecific targeting to allow radiotherapy present are needed.

N-acetylated alpha-linked acidic dipeptidase (NAALADase), also known asglutamate carboxypeptidase II (GCPII) is a neuropeptidase which cleavesN-acetylaspartyl-glutamate (NAAG) into N-acetylaspartate and glutamatein the nervous system, see below, depicting hydrolytic cleavage of NAAGby NAALDase through the tetrahedral intermediate. The enzyme is a typeII protein of the co-catalytic class of metallopeptidases, containingtwo zinc atoms in the active site.

Independent of its characterization in the nervous system, one form ofNAALADase was shown to be expressed at high levels in human prostaticadenocarcinomas and was designated the prostate-specific membraneantigen (PSMA). The NAALADase/PSMA gene is known to produce multiplemRNA splice forms and based on previous immunohistochemical evidence, ithas been assumed that the human brain and prostate expressed differentisoforms of the enzyme.

Human prostate-specific membrane antigen (PSMA), also known as folatehydrolase I (FOLH1), is a trans-membrane, 750 amino acid type IIglycoprotein which is primarily expressed in normal human prostateepithelium but is upregulated in prostate cancer, including metastaticdisease. PSMA is a unique exopeptidase with reactivity towardpoly-gamma-glutamated folates, capable of sequentially removing thepoly-gamma-glutamyl termini. Since PSMA is expressed by virtually allprostate cancers and its expression is further increased in poorlydifferentiated, metastatic and hormone-refractory carcinomas, it is avery attractive target for prostate imaging and therapy. Developingligands that interact with PSMA and carry appropriate radionuclides mayprovide a promising and novel targeting option for the detection,treatment and management of prostate cancer.

The radio-immunoconjugate form of the anti-PSMA monoclonal antibody(mAb) 7E11, known as the PROSTASCINT scan, is currently being used todiagnose prostate cancer metastasis and recurrence. More recently,monoclonal antibodies have been developed that bind to the extracellulardomain of PSMA and have been radiolabeled and shown to accumulate inPSMA-positive prostate tumor models in animals. However, diagnosis andtumor detection using monoclonal antibodies has been limited by the lowpermeability of the monoclonal antibody in solid tumor. Tumor detectionusing low molecular weight radiopharmaceutical compounds, therefore,hold promise and are being explored as potential diagnostic andradiopharmaceutical alternatives to radio-immunoconjugates of monoclonalantibodies.

The selective targeting of cancer cells with radiopharmaceuticals,either for imaging or therapeutic purposes is challenging. A variety ofradionuclides are known to be useful for radio-imaging or cancerradiotherapy, including ¹¹¹In, ⁹⁰Y, ⁶⁸Ga, ¹⁷⁷Lu, ^(99m)Tc, ¹²³I and¹³¹I. Recently it has been shown that some compounds containing aglutamate-urea-glutamate (GUG) or a glutamate-urea-lysine (GUL)recognition element linked to a radionuclide-ligand conjugate exhibithigh affinity for PSMA. Importantly, the present inventors found thatthe avidity of the GUL-radionuclide conjugate and GUG-radionuclideconjugate depends at least in part on the nature and size of the linkeror spacer joining the GUL or GUG moiety to the radionuclide group. Thepresent invention focuses on exploring the relationship between bindingaffinity and linker length as well as the relationship between bindingaffinity and chemical nature of the linker group, as well as on thesynthesis, characterization and methods for using the inventiveGUL-radionuclide and GUG-radionuclide conjugates for the diagnosis andtreatment of diseases.

SUMMARY

In one aspect, compounds are provided that fall within the scope ofFormulae I or II, or their metal complexes. In another aspect, methodsare provided for using pharmaceutically acceptable compositions of theFormulae I or II compounds and/or metal complexes to obtain radiographicimages of one or more regions of a patient.

In one embodiment, a compound represented by Formula II is provided.

In Formula II, X and Y are each independently (CHR¹)_(m) or C(O),substituent W is H, O, —(CHR¹)_(m)—(CH₂)_(p)—, or —(CH₂)_(p)—U and

represents the option of having a double bond. Group L is—C(O)—(C₁-C₁₀)alkylene, —[C(O)—(CH(Z)_(d))—NH]_(j)NR²R³,—C(O)—(CHR¹)—(CH₂)_(p)—U—, —(C₅-C₁₄)aryl-(C₁-C₁₀)alkylene, R⁷-benzylene,—(C₅-C₁₄)heteroaryl-(C₁-C₁₀)alkylene,—C(O)—[(CH₂)_(p)—V]_(n)—(CH₂)_(q)—C(O)—U,[C(O)—CH(Z)_(d)—NH]_(t)—C(O)—(CHR¹)_(m)—(CH₂)_(p)—[U]_(r),—C(S)—NH-benzylene, —C(O)—NH-benzylene,—[C(O)—(CH(Z)_(d))—NH]_(s)-benzylene-, or —(C₁-C₁₀)alkylene-NR⁴R⁵.

In Formula II, T is H, —(C₁-C₁₀)alkylene, RC(O)—(C₁-C₁₀)alkylene,NR²R³—(C₁-C₁₀)alkylene, —(C₅-C₁₄)heteroaryl-(C₁-C₁₀)alkylene,—(C₅-C₁₄)aryl-(C₁-C₁₀)alkylene orR⁶—(C₅-C₁₄)heteroarylene-(C₁-C₁₀)alkylidene, with U being —OR, —COR,—(C₅-C₁₄)arylene or —NR⁴R⁵. V, in Formula II, is —NH—, —NR²— or —NR²R³,and while Z is —(CH₂)_(p)—COOH, —(CH₂)—(C₅-C₁₄)aryl, or —(CH₂)_(p)—NR²R³.

R, R^(a) and R^(b) in Formula II can each independently be —H, —OH,—(C₁-C₁₀)alkyl, —O(C₁-C₁₀)alkyl, —NHR², or —NR²R³; R¹ and R′″ are eachindependently —H, —NH₂, or —(CH₂)_(p)—U; and R², R³, R⁴, R⁵ and R⁶ areeach independently H, bond, (C₁-C₁₀)alkylene, F, Cl, Br, I, C(O), C(S),—C(S)—NH-benzyl-, —C(O)—NH-benzyl-, —C(O)—(C₁-C₁₀)alkylene,—(CH₂)_(v)—NR⁴, —(CH₂)_(p)—NH—C(O)—(CH₂)_(p)—,—(CH₂—CH₂)_(t)—NH—C(O)—(CH₂)_(p)—, —(CH₂)—COR,—(CH₂)_(p)—C(O)NH—C[(CH₂)_(p)—COR]₃, —C[(CH₂)_(p)—COR]₃, or—(CH₂)—(C₅-C₁₄)heteroaryl. In Formula II, R⁷ may be—O(CH₂)_(p)—(C₅-C₁₄)heteroaryl-(CH₂)_(p)—U, and D is a chelator selectedfrom

In Formula II, subscripts d, j, k, m, n, p, q, r, s, t and v are eachindependently 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; and for compounds inaccordance with this formula aryl, arylalkylene, benzyl, heteroaryl, orcycloalkyl is optionally substituted with 1, 2, or 3 substituent groupsselected from the group consisting of —(C₁-C₁₀)alkyl, halogen,—(C₁-C₁₀)halo alkyl, —(C₁-C₁₀) amino alkyl, —(C₁-C₁₀)hydroxyalkyl,—(CH₂)_(p)—C(O)—U and —(C₃-C₈)cyclo alkyl.

Formula II is subject to the proviso that where W is —(CH₂)₅—, L is not—C(O)CH₂—; or where W is —CH(NH₂)—(CH₂)₄—, L is not —C(O)CH₂—.

Metal complexes of any of the compounds of Formula II may also beprovided. Specifically provided are radionuclide complexes of Formula IIcompounds. Illustrative radionuclides are moieties selected from thegroup consisting of ¹¹¹In, ⁹⁰Y, ⁶⁸Ga, ⁶⁴Cu, ¹⁵³Gd, ¹⁵⁵Gd, ¹⁵⁷Gd, Fe and¹⁷⁷Lu. In one aspect, a compound of Formula I is provided or apharmaceutically acceptable salt, ester or solvate thereof.

In the compound of Formula I, X an Y are each independently (CHR¹)_(m)or C(O) and substituent W is H, or —(CH₂)_(p)—U.

Substituent L in Formula I is —C(O)—(C₁-C₁₀)alkylene,—[C(O)—(CH(Z)_(d))—NH]_(j)NR²R³, —C(O)—(CHR¹)—(CH₂)_(p)—U—,—(C₅-C₁₄)aryl-(C₁-C₁₀)alkylene, R⁶O-benzylene,—(C₅-C₁₄)heteroaryl-(C₁-C₁₀)alkylene,—C(O)—[(CH₂)_(p)—V]_(n)—(CH₂)_(q)—C(O)—U or[C(O)—CH(Z)_(d)—NH]_(t)—C(O)—(CHR¹)_(m)—(CH₂)_(p)—U.

For Formula I compounds substituent T is H, —(C₁-C₁₀)alkylene,RC(O)—(C₁-C₁₀)alkylene, NR²R³—(C₁-C₁₀)alkylene,—(C₅-C₁₄)heteroaryl-(C₁-C₁₀)alkylene or —(C₅-C₁₄)aryl-(C₁-C₁₀)alkylene.

For compounds according to Formula I, substituent U is —OH, —OR, —COORor —NR⁴R⁵. V is —NH—, —NR²— or —NR²R³ and Z is —(CH₂)_(p)—COOH, or—(CH₂)_(p)— NR²R³; R is —OH, —O(C₁-C₁₀)alkyl, or NHR².

In Formula I R′ is hydrogen, or an amino (—NH₂) group, while R, R^(a)and R^(b) are each independently —H, —OH, —(C₁-C₁₀)alkyl,—O(C₁-C₁₀)alkyl, or NHR².

For Formula I compounds, substituent R², R³, R⁴ and R⁵ are eachindependently H, bond, (C₁-C₁₀)alkylene, F, Cl, Br, I, C(O), C(S),—C(S)—NH-benzyl-, —C(O)—NH-benzyl-, —C(O)—(C₁-C₁₀)alkylene,—(CH₂)_(p)—NH—C(O)—(CH₂)_(p)—, —(CH₂—CH₂)_(t)—NH—C(O)—(CH₂)_(p)—,—(CH₂)_(p)—COR, —(CH₂)_(p)—C(O)NH—C[(CH₂)_(p)—COR]₃, —C[(CH₂)_(p)—COR]₃,or —(CH₂)_(p)—(C₅-C₁₄)heteroaryl.

When L is R⁶O-benzylene, R⁶ is—O(CH₂)_(p)—(C₅-C₁₄)heteroaryl-(CH₂)_(p)—U.

The chelator D includes any linear, branched, cyclic, or alicyclic,aliphatic polyaza/polycarboxylic acid moiety that is capable of forminga metal complex with a radionuclide. In some embodiments, D includes,but is not limited to:

Subscripts d, j, k, m, n, p and t are integers and are eachindependently 0, 1, 2, 3, 4, 5, or 6.

For Formula I compounds, any aryl, heteroaryl, or cycloalkyl, areoptionally substituted by 1, 2, or 3 substituent groups selected fromthe group consisting of —(C₁-C₁₀)alkyl, —(C₁-C₁₀)haloalkyl, —(C₁-C₁₀)aminoalkyl, —(C₁-C₁₀)hydroxyalkyl, —(CH₂)_(p)—C(O)—U and—(C₃-C₈)cycloalkyl with the proviso that where W is —(CH₂)₅— or—CH(NH₂)—(CH₂)₄—, L is not a —C(O)CH₂— group.

According to certain embodiments substituent T is selected from

When T is

each R′″ is independently

In some embodiments, the compounds of Formula I are complexed with aradionuclide. The radionuclide may include, for example, ¹¹¹In, ⁹⁰Y,⁶⁸Ga, ⁶⁴Cu, ¹⁷⁷Lu, ¹⁵³Gd, ¹⁵⁵Gd, ¹⁵⁷Gd, or Fe.

For Formula I compounds that are not complexed to a radionuclide thefree —C(O)OH groups of the chelator can be esterified to form a prodrug.Illustrative prodrugs include without limitation esters formed usingstraight or branched chain (C₁-C₁₀) alcohols, for example, ethyl esters,propyl esters, isopropyl esters and butyl esters.

Compounds and radionuclide complexes of Formula I compounds and theirpharmaceutical formulations are useful for treating cell proliferativediseases, for example, prostate cancer.

In another aspect, a pharmaceutical formulation is provided includingthe compound of Formula I, a pharmaceutically acceptable salt or solvatethereof, and a pharmaceutically acceptable excipient.

In yet another aspect, a method of obtaining a radiographic image of oneor more regions of a patient is provided by administering to the patientan effective amount of a metal complex of a Formula I compound, or apharmaceutically acceptable salt, ester or solvate thereof, andrecording an image of the one or more regions of the patient. The methodmay be suitable for obtaining a radiographic imaging of one or moretissues that expresses prostate-specific membrane antigen (PSMA) bycontacting the one or more tissues that expresses PSMA with a metalcomplex comprising a radionuclide and a Formula I compound, or apharmaceutically acceptable salt or solvate thereof; and recording aradiographic image of the one or more tissues. The described methodologymay be used to image tissues such as spleen tissue, kidney tissue, orPSMA-expressing tumor tissue.

Another embodiment provides a method for obtaining a radiographic imageof one or more regions of a patient by administering to the patient acompound including a first terminal group having a GUL or GUG moiety, asecond terminal including a chelator moiety complexed with aradionuclide, and a linker connecting the first terminal group to thesecond terminal group, wherein the linker comprises at least twocarboxyl moieties, each having a formula —CO₂J, in which each J may bethe same or different and is independently selected from H, lower alkyland a pharmaceutically acceptable organic or inorganic salt; andrecording a radiographic image of one or more regions of the patient.

Illustrative of chelator moieties include without limitation

groups.

In one embodiment, therefore, the linker comprises at least threecarboxyl moieties.

Another embodiment provides a linker having at least four carboxylmoieties, or a linker that has at least five carboxyl moieties.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates tissue biodistribution of the ¹⁷⁷Lu-complex of(11S,16S,20S)-11-(2-carboxyethyl)-10,13,18-trioxo-1-((4-((1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,9,12,17,19-pentaazadocosane-16,20,22-tricarboxylatein LNCap Xenograft mice.

FIG. 1B illustrates tissue biodistribution of the ¹⁷⁷Lu-complex of(10S,17S,21S)-10-(naphthalen-2-ylmethyl)-8,11,19-trioxo-1-((4-((1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,9,12,18,20-pentaazatricosane-17,21,23-tricarboxylicacid in LNCap Xenograft mice.

FIG. 2 is a graph of the tissue biodistribution of a ¹¹¹In analog of thecompound of Example 3, in LNCap Xenograft mice.

DETAILED DESCRIPTION

There are two categories of radiopharmaceuticals: (i) those withbiological distribution determined strictly by blood flow, or perfusion,and targeting high capacity systems such as glomerular filtration,phagocytosis, hepatocyte clearance and bone absorption and (ii) thosewith distribution determined by specific enzymatic or receptor bindinginteractions, which are low-capacity sites. The radiopharmaceuticalsbelong to the second category and are synthesized by conjugating theradionuclide coordination complex to a biologically active moleculeselective for a particular protein or receptor of interest.

While a variety of biologically active molecules (BAM) can be used asthe carriers, small molecules and small peptides have advantages overantibodies or proteins. For example, small molecules and small peptidesexhibit enhanced diffusion, faster blood clearance, and lower backgroundradiation. These carrier allow the facile synthesis of analogs in ahigh-throughput manner. Additionally, small peptides can be readilyconverted into peptide mimetics or small molecular analogs that haveenhanced stability and improved affinity for the target enzyme orreceptor.

In one aspect, the synthesis and methods for using PSMA selectiveIndium, Ytterbium, Gallium, Copper and Lutetium, Gadolinium and Ironcomplexes of Formula I compounds or Formula II compounds as novelradiopharmaceuticals for the treatment and imaging of cancer cells isprovided. Specifically, the compounds and their radionuclide complexesare suitable for targeting carcinoma of the prostate. It is important tonote that any type of radionuclide can be used so long as an appropriatemetal chelating moiety is available for complexing a particular type ofradionuclide.

The compounds exhibit a high affinity for PSMA expressed on the surfaceof prostate cancer cells. The specificity of Formula I compounds forPSMA is due to the glutamate-urea-glutamate (GUG), orglutamate-urea-lysine (GUL), recognition motif, while affinity isrelated to the nature and size of a linker or spacer group conjugatingthe GUL or GUG moiety to a radionuclide chelator.

The terms “linker,” “spacer,” “linker group” or “spacer group” are usedinterchangeably in this document and refer to a group that spans thedistance between two other identified groups, or which “spaces” themapart. The linker or spacer may be a bond, an organic group, or aninorganic group or atom. In some embodiments, the linker or spacer is anoptionally substituted (C₁-C₁₅)alkylene, a (C₂-C₁₅)alkenylene, or a(C₂-C₁₅)alkynylene group. Illustrative substituent groups includewithout limitation carboxyl groups, carboxylate, hydroxyl groups, andamino (NR²R³) groups. In other embodiments, the linker or spacer is a(C₁-C₁₅)polyol, for example, a polyethylene glycol (PEG) moiety. In yetother embodiments, the linker or spacer includes a backbone of any twoor more of alkyl, nitrogen, carbonyl, and oxygen groups. Such linker orspacer groups are illustrated throughout the examples, although theexamples are only illustrative of the many types of linkers/spacers thatmay be used.

Without ascribing to any particular theory, however, the presentinventors believe that hydrophilic or polar functional groups within thespacer or pendant from the spacer moiety are responsible for enhancingthe affinity of a compound according to the present invention for PSMA.It is also an object of the present invention to provide syntheticmethodologies that provide access to a class of Formula I compoundshaving varying levels of functionality in a rapid syntheticallyaccessible manner.

DEFINITIONS

For convenience, certain terms employed herein and within the appendedclaims are defined here.

As used herein, “about” will be understood by persons of ordinary skillin the art and will vary to some extent depending upon the context inwhich it is used. If there are uses of the term which are not clear topersons of ordinary skill in the art, given the context in which it isused, “about” will mean up to plus or minus 10% of the particular term.

The embodiments, illustratively described herein may suitably bepracticed in the absence of any element or elements, limitation orlimitations, not specifically disclosed herein. Thus, for example, theterms “comprising,” “including,” “containing,” etc. shall be readexpansively and without limitation. Additionally, the terms andexpressions employed herein have been used as terms of description andnot of limitation, and there is no intention in the use of such termsand expressions of excluding any equivalents of the features shown anddescribed or portions thereof, but it is recognized that variousmodifications are possible within the scope of the claimed technology.Additionally, the phrase “consisting essentially of” will be understoodto include those elements specifically recited and those additionalelements that do not materially affect the basic and novelcharacteristics of the claimed technology. The phrase “consisting of”excludes any element not specified.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the elements (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext.

The terms “lipophilic group” and “lipophilic moiety” as used hereinrefer to a group, moiety or substituent that has a greater affinity fornon-polar or non-aqueous environments versus polar or aqueousenvironments. For example, Merriam Webster's online dictionary defines“lipophilic” as “having an affinity for lipids (as fats).” Illustrativelipophilic moieties include aliphatic hydrocarbon radicals, e.g., alkylradicals, aromatic hydrocarbon radicals, and long-chain acyl radicals;all of them have increasing lipophilicity as the number of constituentcarbons increases. In general, addition of a lipophilic moiety to aparticular compound will increase the compound's affinity for octanol inthe standard octanol/water partition-coefficient-determination protocol;this protocol may be used to gauge a compound's relative hydrophobicity(lipophilicity) and hydrophilicity.

The terms “Lewis base” and “Lewis basic” refer to a chemical moietycapable of donating a pair of electrons under certain reactionconditions. It may be possible to characterize a Lewis base as donatinga single electron in certain complexes, depending on the identity of theLewis base and the metal ion, but for most purposes, however, a Lewisbase is best understood as a two electron donor. Examples of Lewis basicmoieties include uncharged compounds such as alcohols, thiols, andamines, and charged moieties such as alkoxides, thiolates, carbanions,and a variety of other organic anions. In certain examples, a Lewis basemay consist of a single atom, such as oxide (O₂ ⁻). In certain, lesscommon circumstances, a Lewis base or ligand may be positively charged.A Lewis base, when coordinated to a metal ion, is often referred to as aligand.

The term “ligand” refers to a species that interacts in some fashionwith another species. In one example, a ligand may be a Lewis base thatis capable of forming a coordinate bond with a Lewis Acid. In otherexamples, a ligand is a species, often organic, that forms a coordinatebond with a metal ion. Ligands, when coordinated to a metal ion, mayhave a variety of binding modes know to those of skill in the art, whichinclude, for example, terminal (i.e., bound to a single metal ion) andbridging (i.e., one atom of the Lewis base bound to more than one metalion).

The term “chelating agent” refers to a molecule, often an organic one,and often a Lewis base, having two or more unshared electron pairsavailable for donation to a metal ion. The metal ion is usuallycoordinated by two or more electron pairs to the chelating agent. Theterms, “bidentate chelating agent”, “tridentate chelating agent”, and“tetradentate chelating agent” are art-recognized and refer to chelatingagents having, respectively, two, three, and four electron pairs readilyavailable for simultaneous donation to a metal ion coordinated by thechelating agent. Usually, the electron pairs of a chelating agent formscoordinate bonds with a single metal ion; however, in certain examples,a chelating agent may form coordinate bonds with more than one metalion, with a variety of binding modes being possible.

The term “coordination” refers to an interaction in which onemulti-electron pair donor coordinatively bonds (is “coordinated”) to onemetal ion.

The term radionuclide refers to an atom with an unstable nucleus, whichis a nucleus characterized by excess energy available to be impartedeither to a newly created radiation particle within the nucleus or to anatomic electron. The radionuclide can undergo radioactive decay and inthe process emit subatomic ionizing particles. Illustrative of subatomicionizing particles without limitation are alpha (α) particles, beta (β)particle and gamma (γ) rays. Illustrative radionuclides may include, butare not limited to ¹¹¹In, ⁹⁰Y, ⁶⁸Ga, ⁶⁴Cu, ¹⁷¹Lu, ^(153/157/158)Gd, orFe. However, the term is not limited to these four radionuclides.

Fmoc is an abbreviation for the chemical group:fluorenylmethyloxycarbonyl.

The phrases “effective amount” or “therapeutically-effective amount” asused herein means that amount of a compound, material, or compositioncomprising a compound of the invention, or other active ingredient whichis effective for producing some desired therapeutic effect in at least asub-population of cells in an animal at a reasonable benefit/risk ratioapplicable to any medical treatment. A therapeutically effective amountwith respect to a compound of the invention means that amount oftherapeutic agent alone, or in combination with other therapies, thatprovides a therapeutic benefit in the treatment or prevention of adisease. Used in connection with a compound of the invention, the termcan encompass an amount that improves overall therapy, reduces or avoidssymptoms or causes of disease, or enhances the therapeutic efficacy ofor synergies with another therapeutic agent.

As used herein, the terms “treating” or “treatment” is intended toencompass also diagnosis, prophylaxis, therapy and cure. The patientreceiving this treatment is any animal in need, including primates, inparticular humans, and other mammals such as equines, cattle, swine andsheep; and poultry and pets in general.

The terms “prevent,” “preventing,” and “prevention” refer to theprevention of the onset, recurrence, or spread of the disease in apatient resulting from the administration of a prophylactic ortherapeutic agent.

The phrase “pharmaceutically acceptable” is employed herein to refer tothose compounds, materials, compositions, and/or dosage forms which are,within the scope of sound medical judgment, suitable for use in contactwith the tissues of human beings and animals without excessive toxicity,irritation, allergic response, or other problem or complication,commensurate with a reasonable benefit/risk ratio.

The phrase “pharmaceutically-acceptable carrier” as used herein means apharmaceutically-acceptable material, composition or vehicle, such as aliquid or solid filler, diluent, excipient, or solvent encapsulatingmaterial, involved in carrying or transporting the subject compound fromone organ, or portion of the body, to another organ, or portion of thebody. Each carrier must be “acceptable” in the sense of being compatiblewith the other ingredients of the formulation and not injurious to thepatient. Some examples of materials which can serve aspharmaceutically-acceptable carriers include: (1) sugars, such aslactose, glucose and sucrose; (2) starches, such as corn starch andpotato starch; (3) cellulose, and its derivatives, such as sodiumcarboxymethyl cellulose, ethyl cellulose and cellulose acetate; (4)powdered tragacanth; (5) malt; (6) gelatin; (7) talc; (8) excipients,such as cocoa butter and suppository waxes; (9) oils, such as peanutoil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil andsoybean oil; (10) glycols, such as propylene glycol; (11) polyols, suchas glycerin, sorbitol, mannitol and polyethylene glycol; (12) esters,such as ethyl oleate and ethyl laurate; (13) agar; (14) bufferingagents, such as magnesium hydroxide and aluminum hydroxide; (15) alginicacid; (16) pyrogen-free water; (17) isotonic saline; (18) Ringer'ssolution; (19) ethyl alcohol; (20) pH buffered solutions; (21)polyesters, polycarbonates and/or polyanhydrides; and (22) othernon-toxic compatible substances employed in pharmaceutical formulations.

A “pharmaceutically acceptable salt” is a pharmaceutically acceptable,organic or inorganic acid or base salt of a compound of the invention.Representative pharmaceutically acceptable salts include, e.g., alkalimetal salts, alkali earth salts, ammonium salts, water-soluble andwater-insoluble salts, such as the acetate, amsonate(4,4-diaminostilbene-2,2-disulfonate), benzenesulfonate, benzonate,bicarbonate, bisulfate, bitartrate, borate, bromide, butyrate, calcium,calcium edetate, camsylate, carbonate, chloride, citrate, clavulariate,dihydrochloride, edetate, edisylate, estolate, esylate, fumarate,gluceptate, gluconate, glutamate, glycollylarsanilate,hexafluorophosphate, hexylresorcinate, hydrabamine, hydrobromide,hydrochloride, hydroxynaphthoate, iodide, isothionate, lactate,lactobionate, laurate, malate, maleate, mandelate, mesylate,methylbromide, methylnitrate, methylsulfate, mucate, napsylate, nitrate,N-methylglucamine ammonium salt, 3-hydroxy-2-naphthoate, oleate,oxalate, palmitate, pamoate (1,1-methene-bis-2-hydroxy-3-naphthoate,einbonate), pantothenate, phosphate/diphosphate, picrate,polygalacturonate, propionate, p-toluenesulfonate, salicylate, stearate,subacetate, succinate, sulfate, sulfosalicylate, suramate, tannate,tartrate, teoclate, tosylate, triethiodide, and valerate salts. Apharmaceutically acceptable salt can have more than one charged atom inits structure. In this instance the pharmaceutically acceptable salt canhave multiple counterions. Thus, a pharmaceutically acceptable salt canhave one or more charged atoms and/or one or more counterions.

The phrases “parenteral administration” and “administered parenterally”as used herein means modes of administration other than enteral andtopical administration, usually by injection, and includes, withoutlimitation, intravenous, intramuscular, intraarterial, intrathecal,intracapsular, intraorbital, intracardiac, intradermal, intraperitoneal,transtracheal, subcutaneous, subcuticular, intraarticulare, subcapsular,subarachnoid, intraspinal and intrasternal injection and infusion.

The phrases “systemic administration,” “administered systemically,”“peripheral administration” and “administered peripherally” as usedherein mean the administration of a compound, drug or other materialother than directly into the central nervous system, such that it entersthe patient's system and, thus, is subject to metabolism and other likeprocesses, for example, subcutaneous administration.

The term “amino acid” refers to all compounds, whether natural orsynthetic, which include both an amino functionality and an acidfunctionality, including amino acid analogs and derivatives.Illustrative of compounds that fall within this genus without limitationare L-amino acide, D-amino acids, α-amino acids, β-amino acid, as wellas γ-amino acids.

A “patient” includes an animal, such as a human, cow, horse, sheep,lamb, pig, chicken, turkey, quail, cat, dog, mouse, rat, rabbit orguinea pig. The animal can be a mammal such as a non-primate and aprimate (e.g., monkey and human). In one embodiment, a patient is ahuman, such as a human infant, child, adolescent or adult.

The term “prodrug” refers to a precursor of a drug that is a compoundwhich upon administration to a patient, must undergo chemical conversionby metabolic processes before becoming an active pharmacological agent.Illustrative prodrugs of compounds in accordance with Formula I areesters and amides, preferably alkyl esters or fatty acid esters.

The term “heteroatom” refers to an atom of any element other than carbonor hydrogen. Illustrative heteroatoms include boron, nitrogen, oxygen,phosphorus, sulfur and selenium.

In general, “substituted” refers to an alkyl or alkenyl group, asdefined below (e.g., an alkyl group) in which one or more bonds to ahydrogen atom contained therein are replaced by a bond to non-hydrogenor non-carbon atoms. Substituted groups also include groups in which oneor more bonds to a carbon(s) or hydrogen(s) atom are replaced by one ormore bonds, including double or triple bonds, to a heteroatom. Thus, asubstituted group will be substituted with one or more substituents,unless otherwise specified. In some embodiments, a substituted group issubstituted with 1, 2, 3, 4, 5, or 6 substituents. Examples ofsubstituent groups include: halogens (i.e., F, Cl, Br, and I);hydroxyls; alkoxy, alkenoxy, alkynoxy, aryloxy, aralkyloxy,heterocyclyloxy, and heterocyclylalkoxy groups; carbonyls (oxo);carboxyls; esters; urethanes; oximes; hydroxylamines; alkoxyamines;aralkoxyamines; thiols; sulfides; sulfoxides; sulfones; sulfonyls;sulfonamides; amines; N-oxides; hydrazines; hydrazides; hydrazones;azides; amides; ureas; amidines; guanidines; enamines; imides;isocyanates; isothiocyanates; cyanates; thiocyanates; imines; nitrogroups; nitriles (i.e., CN), haloalkyl, aminoalkyl, hydroxyalkyl,cycloalkyl and the like.

Alkyl groups include straight chain and branched chain alkyl groupshaving from 1 to 12 carbon atoms, and typically from 1 to 10 carbons or,in some embodiments, from 1 to 8, 1 to 6, or 1 to 4 carbon atoms.Examples of straight chain alkyl groups include groups such as methyl,ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, and n-octylgroups. Examples of branched alkyl groups include, but are not limitedto, isopropyl, iso-butyl, sec-butyl, tert-butyl, neopentyl, isopentyl,and 2,2-dimethylpropyl groups. Alkyl groups may be substituted orunsubstituted. Unless the number of carbons is otherwise specified,“lower alkyl” refers to an alkyl group, as defined above, but havingfrom one to about ten carbons, alternatively from one to about sixcarbon atoms in its backbone structure. Likewise, “lower alkenyl” and“lower alkynyl” have similar chain lengths.

The terms “alkylene” and “substituted alkylene” refer to divalent alkyland divalent substituted alkyl, respectively. Examples of alkyleneinclude without limitation, ethylene (—CH₂—CH₂—). “Optionallysubstituted alkylene” refers to alkylene or substituted alkylene.

The term “alkylcarbonyl” denotes an —(C₁-C₈)alkyl-C(O) group in whichone or more methylenes in the C₁-C₈ alkyl group is replaced with a C(O)group. Representative examples include, but are not limited to, acetyl,propionyl, and CH₃(CH₂)₂C(O)— group.

The terms “cyclic alkyl” or “cycloalkyl” refers to a saturated orpartially saturated non-aromatic cyclic alkyl groups of from 3 to 14carbon atoms and no ring heteroatoms and having a single ring ormultiple rings including fused and bridged ring systems. Cycloalkylgroups may be substituted or unsubstituted. Cycloalkyl or cyclic alkylgroups include mono-, bi- or tricyclic alkyl groups having from 3 to 14carbon atoms in the ring(s), or, in some embodiments, 3 to 12, 3 to 10,3 to 8, or 3 to 4, 5, 6 or 7 carbon atoms. Illustrative monocycliccycloalkyl groups include, but not limited to, cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups. Bi- andtricyclic ring systems include both bridged cycloalkyl groups and fusedrings, such as, but not limited to, bicyclo[2.1.1]hexane, adamantyl,decalinyl, and the like.

Alkenyl groups include straight and branched chain and cycloalkyl groupsas defined above, except that at least one double bond exists betweentwo carbon atoms. Thus, alkenyl groups have from 2 to about 12 carbonatoms in some embodiments, from 2 to 10 carbon atoms in otherembodiments, and from 2 to 8 carbon atoms in other embodiments. Examplesinclude, but are not limited to vinyl, allyl, —CH═CH(CH₃), —CH═C(CH₃)₂,—C(CH₃)═CH₂, —C(CH₃)═CH(CH₃), —C(CH₂CH₃)═CH₂, cyclohexenyl,cyclopentenyl, cyclohexadienyl, butadienyl, pentadienyl, and hexadienyl,among others. Alkenyl groups may be substituted or unsubstituted.Representative substituted alkenyl groups may be mono-substituted orsubstituted more than once, such as, but not limited to, mono-, di- ortri-substituted with substituents such as those listed above.

The term “alkenylene” refers to divalent alkene. Examples of alkenyleneinclude without limitation, ethenylene (—CH═CH—) and all stereoisomericand conformational isomeric forms thereof. “Substituted alkenylene”refers to divalent substituted alkene. “Optionally substitutedalkenylene” refers to alkenylene or substituted alkenylene.

“Alkyne” or “alkynyl” refers to straight and branched chain unsaturatedhydrocarbon having the indicated number of carbon atoms and at least onetriple bond. Examples of a (C₂-C₈)alkynyl group include, but are notlimited to, acetylene, propyne, 1-butyne, 2-butyne, 1-pentyne,2-pentyne, 1-hexyne, 2-hexyne, 3-hexyne, 1-heptyne, 2-heptyne,3-heptyne, 1-octyne, 2-octyne, 3-octyne and 4-octyne. An alkynyl groupcan be unsubstituted or optionally substituted with one or moresubstituents as described herein below.

The term “alkynylene” refers to divalent alkyne. Examples of alkynyleneinclude without limitation, ethynylene, propynylene. “Substitutedalkynylene” refers to divalent substituted alkyne.

Aryl groups are cyclic aromatic hydrocarbons that do not containheteroatoms. Aryl groups include monocyclic, bicyclic and polycyclicring systems. Thus, aryl groups include, but are not limited to, phenyl,azulenyl, heptalenyl, biphenylenyl, indacenyl, fluorenyl, phenanthrenyl,triphenylenyl, pyrenyl, naphthacenyl, chrysenyl, biphenyl, anthracenyl,indenyl, indanyl, pentalenyl, and naphthyl groups. In some embodiments,aryl groups contain 6-14 carbons, and in others from 6 to 12 or even6-10 carbon atoms in the ring portions of the groups. Aryl groupincludes both substituted and unsubstituted aryl groups. Substitutedaryl groups may be mono-substituted or substituted more than once. Forexample, monosubstituted aryl groups include, but are not limited to,2-, 3-, 4-, 5-, or 6-substituted phenyl or naphthyl groups, which may besubstituted with substituent groups such as those listed above.

Aralkyl groups are alkyl groups as defined above in which a hydrogen orcarbon bond of an alkyl group is replaced with a bond to an aryl groupas defined above. In some embodiments, aralkyl groups contain 7 to 20carbon atoms, 7 to 14 carbon atoms or 7 to 10 carbon atoms.

“Heterocyclyl” or heterocycloalkyl refers to non-aromatic ring compoundscontaining 3 or more ring members, of which one or more ring carbonatoms are replaced with a heteroatom such as, but not limited to, N, O,and S. In some embodiments, heterocyclyl groups include 3 to 20 ringmembers, whereas other such groups have 3 to 6, 3 to 10, 3 to 12, or 3to 15 ring members. Heterocyclyl groups encompass unsaturated, partiallysaturated and saturated ring systems, such as, for example, imidazolyl,imidazolinyl and imidazolidinyl groups. Heterocyclyl groups may besubstituted or unsubstituted. Heterocyclyl groups include, but are notlimited to, aziridinyl, azetidinyl, pyrrolidinyl, imidazolidinyl,pyrazolidinyl, thiazolidinyl, tetrahydrothiophenyl, tetrahydrofuranyl,dioxolyl, furanyl, thiophenyl, pyrrolyl, pyrrolinyl, imidazolyl,imidazolinyl, pyrazolyl, pyrazolinyl, triazolyl, tetrazolyl, oxazolyl,isoxazolyl, thiazolyl, thiazolinyl, isothiazolyl, thiadiazolyl,oxadiazolyl, piperidyl, piperazinyl, morpholinyl, thiomorpholinyl,tetrahydropyranyl, tetrahydrothiopyranyl, oxathiane, dioxyl, dithianyl,pyranyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl,dihydropyridyl, dihydrodithiinyl, dihydrodithionyl, homopiperazinyl,quinuclidyl, indolyl, indolinyl, isoindolyl, azaindolyl(pyrrolopyridyl), indazolyl, indolizinyl, benzotriazolyl,benzimidazolyl, benzofuranyl, benzothiophenyl, benzthiazolyl,benzoxadiazolyl, benzoxazinyl, benzodithiinyl, benzoxathiinyl,benzothiazinyl, benzoxazolyl, benzothiazolyl, benzothiadiazolyl,benzo[1,3]dioxolyl, pyrazolopyridyl, imidazopyridyl (azabenzimidazolyl),triazolopyridyl, isoxazolopyridyl, purinyl, xanthinyl, adeninyl,guaninyl, quinolinyl, isoquinolinyl, quinolizinyl, quinoxalinyl,quinazolinyl, cinnolinyl, phthalazinyl, naphthyridinyl, pteridinyl,thianaphthalenyl, dihydrobenzothiazinyl, dihydrobenzofuranyl,dihydroindolyl, dihydrobenzodioxinyl, tetrahydroindolyl,tetrahydroindazolyl, tetrahydrobenzimidazolyl, tetrahydrobenzotriazolyl,tetrahydropyrrolopyridyl, tetrahydropyrazolopyridyl,tetrahydroimidazopyridyl, tetrahydrotriazolopyridyl, andtetrahydroquinolinyl groups. Heterocyclyl groups may be substituted orunsubstituted. Representative substituted heterocyclyl groups may bemono-substituted or substituted more than once, such as, but not limitedto, pyridyl or morpholinyl groups, which are 2-, 3-, 4-, 5-, or6-substituted, or disubstituted with various substituents such as thoselisted above.

Heteroaryl groups are aromatic ring compounds containing 5 or more ringmembers, of which, one or more ring carbon atoms are replaced withheteroatom such as, but not limited to, N, O, and S. Heteroaryl groupsmay be substituted or unsubstituted. Heteroaryl groups include, but arenot limited to, groups such as pyrrolyl, pyrazolyl, triazolyl,tetrazolyl, oxazolyl, isoxazolyl, thiazolyl, pyridyl, pyridazinyl,pyrimidinyl, pyrazinyl, thiophenyl, benzothiophenyl, furanyl,benzofuranyl, indolyl, azaindolyl (pyrrolopyridyl), indazolyl,benzimidazolyl, imidazopyridyl (azabenzimidazolyl), pyrazolopyridyl,triazolopyridyl, benzotriazolyl, benzoxazolyl, benzothiazolyl,benzothiadiazolyl, imidazopyridyl, isoxazolopyridyl, thianaphthalenyl,purinyl, xanthinyl, adeninyl, guaninyl, quinolinyl, isoquinolinyl,tetrahydroquinolinyl, quinoxalinyl, and quinazolinyl groups.

Alkoxy groups are hydroxyl groups (—OH) in which the bond to thehydrogen atom is replaced by a bond to a carbon atom of a substituted orunsubstituted alkyl group as defined above. Examples of linear alkoxygroups include but are not limited to methoxy, ethoxy, propoxy, butoxy,pentoxy, hexoxy, and the like. Examples of branched alkoxy groupsinclude but are not limited to isopropoxy, sec-butoxy, tert-butoxy,isopentoxy, isohexoxy, and the like. Examples of cycloalkoxy groupsinclude but are not limited to cyclopropyloxy, cyclobutyloxy,cyclopentyloxy, cyclohexyloxy, and the like. Alkoxy groups may besubstituted or unsubstituted. Representative substituted alkoxy groupsmay be substituted one or more times with substituents such as thoselisted above.

The term “carbocycle” refers to an aromatic or non-aromatic ring inwhich each atom of the ring is carbon.

The term “nitro” refers to —NO₂; the term “halogen” is art-recognizedand refers to —F, —Cl, —Br or —I; the term “sulfhydryl” isart-recognized and refers to —SH; the term “hydroxyl” means —OH; and theterm “sulfonyl” is art-recognized and refers to —SO₂ ⁻. “Halide”designates the corresponding anion of the halogens, and “pseudohalide”has the definition set forth on 560 of “Advanced Inorganic Chemistry” byCotton and Wilkinson.

The term “amine or amino” refers to an —NR^(c)R^(d) group wherein R^(c)and R^(d) each independently refer to a hydrogen, (C₁-C₈)alkyl, aryl,heteroaryl, and heterocycloalkyl group. When R^(c) and R^(d) areattached to the same nitrogen atom, they can be combined with thenitrogen atom to form a 5-, 6-, or 7-membered ring. For example,—NR^(c)R^(d) is meant to include 1-pyrrolidinyl, pyridinyl or a4-morpholinyl ring.

The term “amido” is art recognized as an amino-substituted carbonyl andincludes a moiety that may be represented by the general formula,—C(O)NR^(c)R^(d) group wherein R^(c) and R^(d) are as defined above.According to some embodiments, the amide does not include imides whichmay be unstable.

The term ‘nitrile or cyano” can be used interchangeably and refer to a—CN group which is bound to a carbon atom of a heteroaryl ring, arylring and a heterocycloalkyl ring.

The term “aminoalkyl,” refers to an (C₁-C₁₀)alkyl group wherein one ormore hydrogen atoms in the (C₁-C₁₀)alkyl group is replaced with a—NR^(d)R^(e) group, where R^(d) and R^(e) can be the same or different,for example, R^(d) and R^(e) each independently refer to a hydrogen,(C₁-C₈)alkyl, aryl, heteroaryl, heterocycloalkyl, (C₁-C₈)haloalkyl, and(C₁-C₁₀)hydroxyalkyl group. Examples of aminoalkyl groups include, butare not limited to, aminomethyl, aminoethyl, 4-aminobutyl and3-aminobutylyl.

The term “haloalkoxy,” refers to an —O—(C₁-C₈)alkyl group wherein one ormore hydrogen atoms in the C₁-C₈ alkyl group is replaced with a halogenatom, which can be the same or different. Examples of haloalkyl groupsinclude, but are not limited to, difluoromethocy, trifluoromethoxy,2,2,2-trifluoroethoxy, 4-chlorobutoxy, 3-bromopropyloxy,pentachloroethoxy, and 1,1,1-trifluoro-2-bromo-2-chloro ethoxy.

The term “hydroxyalkyl,” refers to an alkyl group having the indicatednumber of carbon atoms wherein one or more of the alkyl group's hydrogenatoms is replaced with an —OH group. Examples of hydroxyalkyl groupsinclude, but are not limited to, —CH₂OH, —CH₂CH₂OH, —CH₂CH₂CH₂OH,—CH₂CH₂CH₂CH₂OH, —CH₂CH₂CH₂CH₂CH₂OH, —CH₂CH₂CH₂CH₂CH₂CH₂OH, and branchedversions thereof.

A “hydroxyl” or “hydroxy” refers to an —OH group.

The terms “carboxyl” and “carboxylate” include such moieties as may berepresented by the general formulas:

wherein E is a bond or represents O or S, and R^(f) and R^(f′)individually is H, alkyl, alkenyl, aryl, or a pharmaceuticallyacceptable salt. Where E is O, and R^(f) is as defined above, the moietyis referred to herein as a carboxyl group, and particularly when R^(f)is a hydrogen, the formula represents a “carboxylic acid”. In general,where the expressly shown oxygen is replaced by sulfur, the formularepresents a “thiocarbonyl” group.

The substituent —CO₂H, may be replaced with bioisosteric replacementssuch as:

and the like, wherein R has the same definition as R′ and R″ as definedherein. See, e.g., THE PRACTICE OF MEDICINAL CHEMISTRY (Academic Press:New York, 1996), at page 203.

The terms “alkoxyl” or “alkoxy” refer to an alkyl group, as definedabove, having an oxygen radical attached thereto. Representative alkoxylgroups include methoxy, ethoxy, propoxy, butyoxy, tert-butoxy and thelike. An “ether” is two hydrocarbons covalently linked by an oxygen.“Ether” also encompasses polyethers where more than one ether group, orlinkage, may be present in a given group. “Ether” also encompassescyclic ethers, and crown ethers, where the ether linkage is within acyclic group.

The term “(C₅-C₁₄)aryl-(C₁-C₁₀)alkylene” refers to a divalent alkylenewherein one or more hydrogen atoms in the C₁-C₁₀ alkylene group isreplaced by a (C₃-C₁₄)aryl group. Examples of(C₃-C₁₄)aryl-(C₁-C₁₀)alkylene groups include without limitation1-phenylbutylene, phenyl-2-butylene, 1-phenyl-2-methylpropylene,phenylmethylene, phenylpropylene, and naphthylethylene.

The term “(C₅-C₁₄)heteroaryl-(C₁-C₁₀)alkylene” refers to a divalentalkylene wherein one or more hydrogen atoms in the C₁-C₁₀ alkylene groupis replaced a (C₃-C₁₄)heteroaryl group. Examples of(C₃-C₁₄)heteroaryl-(C₁-C₁₀)alkylene groups include without limitation1-pyridylbutylene, quinolinyl-2-butylene and1-pyridyl-2-methylpropylene.

The term “—(C₅-C₁₄)heteroarylene-(C₁-C₁₀)alkylene-” refers to a divalentalkylene wherein one or more hydrogen atoms in the C₁-C₁₀ alkylene groupis replaced a (C₃-C₁₄)heteroaryl group and wherein one of the hydrogensor one of the heteroatoms of the (C₃-C₁₄)heteroaryl group is bonded toanother group, for example, a (C₁-C₁₀)alkyl group.

A “benzyl” is

while the term “benzylene” denotes a divalent benzyl moiety that isrepresented by the following structure

A halogen refers to chlorine, bromine, fluorine, or iodine.

The definition of each expression, e.g. alkyl, m, n, and the like, whenit occurs more than once in any structure, is intended to be independentof its definition elsewhere in the same structure.

The terms triflyl, tosyl, mesyl, and nonaflyl refer totrifluoromethanesulfonyl, p-toluenesulfonyl, methanesulfonyl, andnonafluorobutanesulfonyl groups, respectively. The terms triflate,tosylate, mesylate, and nonaflate are art-recognized and refer totrifluoromethanesulfonate ester, p-toluenesulfonate ester,methanesulfonate ester, and nonafluorobutanesulfonate ester functionalgroups and molecules that contain the groups, respectively. Theabbreviations Me, Et, Ph, Tf, Nf, Ts, and Ms represent methyl, ethyl,phenyl, trifluoromethanesulfonyl, nonafluorobutanesulfonyl,p-toluenesulfonyl and methanesulfonyl, respectively. A morecomprehensive list of the abbreviations utilized by organic chemists ofordinary skill in the art appears in the first issue of each volume ofthe Journal of Organic Chemistry; this list is typically presented in atable entitled Standard List of Abbreviations.

Certain compounds contained in the compositions may exist in particulargeometric or stereoisomeric forms. In addition, compounds may also beoptically active. The compounds may also include cis- and trans-isomers,R- and S-enantiomers, diastereomers, (D)-isomers, (L)-isomers, theracemic mixtures thereof, and other mixtures thereof. Additionalasymmetric carbon atoms may be present in a substituent such as an alkylgroup. If, for instance, a particular enantiomer of compound is desired,it may be prepared by asymmetric synthesis, or by derivation with achiral auxiliary, where the resulting diastereomeric mixture isseparated and the auxiliary group cleaved to provide the pure desiredenantiomers. Alternatively, where the molecule contains a basicfunctional group, such as amino, or an acidic functional group, such ascarboxyl, diastereomeric salts are formed with an appropriateoptically-active acid or base, followed by resolution of thediastereomers thus formed by fractional crystallization orchromatographic means well known in the art, and subsequent recovery ofthe pure enantiomers.

The phrase “protecting group” as used herein means temporarysubstituents which protect a potentially reactive functional group fromundesired chemical transformations. Examples of such protecting groupsinclude esters of carboxylic acids, silyl ethers of alcohols, andacetals and ketals of aldehydes and ketones, respectively. The field ofprotecting group chemistry has been reviewed (Greene, T. W.; Wuts, P. G.M. Protective Groups in Organic Synthesis, 3^(rd) ed.; Wiley: New York,1999).

Unless otherwise indicated, “stereoisomer” means one stereoisomer of acompound that is substantially free of other stereoisomers of thatcompound. Thus, a stereomerically pure compound having one chiral centerwill be substantially free of the opposite enantiomer of the compound. Astereomerically pure compound having two chiral centers will besubstantially free of other diastereomers of the compound. A typicalstereomerically pure compound comprises greater than about 80% by weightof one stereoisomer of the compound and less than about 20% by weight ofother stereoisomers of the compound, for example greater than about 90%by weight of one stereoisomer of the compound and less than about 10% byweight of the other stereoisomers of the compound, or greater than about95% by weight of one stereoisomer of the compound and less than about 5%by weight of the other stereoisomers of the compound, or greater thanabout 97% by weight of one stereoisomer of the compound and less thanabout 3% by weight of the other stereoisomers of the compound.

If there is a discrepancy between a depicted structure and a name giventhat structure, then the depicted structure controls. Additionally, ifthe stereochemistry of a structure or a portion of a structure is notindicated with, for example, bold or dashed lines, the structure orportion of the structure is to be interpreted as encompassing allstereoisomers of it.

Chelator Compounds and their Synthesis

The present technology is directed to Formula I and Formula II compoundsand their pharmaceutically acceptable salts, esters or solvates. BothFormula I and Formula II compounds are potent ligands for radioimagingapplications and for radiotherapeutic applications of PSMA expressingprostate cancer tissue. The compounds include a first terminal group anda second terminal group that are connected using a linker or spacer. Thefirst terminal group is a tripeptide comprising a glutamic-urea-lysine(GUL), or glutamic-urea-glutamic (GUG) moiety (see below), while thesecond terminal group comprises a radionuclide chelator.

In one embodiment, the compounds are represented by Formula II.

In Formula II, X and Y are each independently (CHR¹)_(m) or C(O),substituent W is H, O, —(CHR¹)_(m)—(CH₂)_(p)—, or —(CH₂)_(p)—U and

represents the option of having a double bond. Group L is selected from—C(O)—(C₁-C₁₀)alkylene, —[C(O)—(CH(Z)_(d))—NH]_(j)NR²R³,—C(O)—(CHR¹)—(CH₂)_(p)—U—, —(C₅-C₁₄)aryl-(C₁-C₁₀)alkylene, R⁷-benzylene,—(C₅-C₁₄)heteroaryl-(C₁-C₁₀)alkylene,—C(O)—[(CH₂)_(p)—V]_(n)—(CH₂)_(q)—C(O)—U,[C(O)—CH(Z)_(d)—NH]_(t)—C(O)—(CHR¹)_(m)—(CH₂)_(p)—[U]_(r),—C(S)—NH-benzylene, —C(O)—NH-benzylene,—[C(O)—(CH(Z)_(d))—NH]_(s)-benzylene-, or —(C₁-C₁₀)alkylene-NR⁴R⁵.

In Formula II, T is selected from the group consisting of H,—(C₁-C₁₀)alkylene, RC(O)—(C₁-C₁₀)alkylene, NR²R³—(C₁-C₁₀)alkylene,—(C₅-C₁₄)heteroaryl-(C₁-C₁₀)alkylene, —(C₅-C₁₄)aryl-(C₁-C₁₀)alkylene andR⁶—(C₅-C₁₄)heteroarylene-(C₁-C₁₀)alkylidene, with U being selected fromthe group consisting of —OR, —COR, —(C₅-C₁₄)arylene and —NR⁴R⁵.

Substituent V is selected from the group consisting of —NH—, —NR²— and—NR²R³, while group Z can be —(CH₂)_(p)—COOH, —(CH₂)_(p)—(C₅-C₁₄)aryl,or —(CH₂)_(p)—NR²R³.

R, R^(a) and R^(b) in Formula II compounds can each independently be —H,—OH, —(C₁-C₁₀)alkyl, —O(C₁-C₁₀)alkyl, —NHR², or —NR²R³. Substituents R¹and R′″ are each independently —H, —NH₂, or —(CH₂)_(p)—U and groups R²,R³, R⁴, R⁵ and R⁶ each independently being H, bond, (C₁-C₁₀)alkylene, F,Cl, Br, I, C(O), C(S), —C(S)—NH-benzyl-, —C(O)—NH-benzyl-,—C(O)—(C₁-C₁₀)alkylene, —(CH₂)_(v)—NR⁴, —(CH₂)_(p)—NH—C(O)—(CH₂)_(p)—,—(CH₂—CH₂)_(t)—NH—C(O)—(CH₂)_(p)—, —(CH₂)_(p)—COR,—(CH₂)_(p)—C(O)NH—C[(CH₂)_(p)—COR]₃, —C[(CH₂)_(p)—COR]₃, or—(CH₂)_(p)(C₅-C₁₄)heteroaryl with R⁷ in Formula II being—O(CH₂)_(p)—(C₅-C₁₄)heteroaryl-(CH₂)_(p)—U.

To form complexes, Formula II provides chelator group D that caninteract and complex radionuclides. Illustrative of such chelators arecompounds selected from

In Formula II, subscripts d, j, k, m, n, p, q, r, s, t and v are eachindependently 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. Moreover, any aryl,arylalkylene, benzyl, heteroaryl, or cycloalkyl in a Formula II compoundcan optionally be substituted with 1, 2, or 3 substituent groupsselected from the group consisting of —(C₁-C₁₀)alkyl, halogen,—(C₁-C₁₀)haloalkyl, —(C₁-C₁₀) aminoalkyl, —(C₁-C₁₀)hydroxyalkyl,—(CH₂)_(p)—C(O)—U and —(C₃-C₈)cycloalkyl.

Illustrative compounds of Formula II include, but are not limited to:

In one embodiment, L is —C(O)—(CHR¹)—(CH₂)_(p)—U— with R¹ being —H andsubscript p being an integer between 1-10 both numbers inclusive. GroupU according to this embodiment is —NR⁴R⁵ with either substituent R⁴ orR⁵ being hydrogen and the other substituent being a —C(S)NH-bezyl-group.Exemplary of such a linker is

where p is 4. For certain Formula II compounds [>—W]_(k) is a—(CH₂)_(p)—U group with k being 2. In the first instance, U is a—(CH₂)_(p)—C(O)R group with R being —OH and p being 1. In the secondinstance U is an aryl group, for example an optionally substitutedbenzyl group.

An illustrative Formula II compound that comports with the abovedefinition is illustrated below:

While the structures of Formula II compounds above do not illustratepharmaceutically acceptable salts and/or solvates of the inventivecompounds, it is within the scope of the present invention to encompasspharmaceutically acceptable salt forms and/or solvates. In someembodiments, the chelator group, for example, the DOTA group is notcomplexed with a radionuclide. In one embodiment, therefore, when DOTAis un-complexed the carboxylic acid groups of the DOTA group can be inthe form of a free acid, or in the form of a salt. The free carboxylicacid groups can also be esterified to obtain the prodrug form of FormulaI compounds. Suitable ester prodrugs include various alkyl esters,including saturated and unsaturated C₈ to C₁₈ fatty acids.

The inventive compounds are glutamate-urea-lysine (GUL-) orglutamate-urea-glutamate (GUG) analogs in which a chelator group isconjugated to the GUL- or GUG-moiety via a linker.

As further discussed below, the length and chemical nature of the linkergroup is believed to influence the binding avidity of Formula IIcompounds to the target tissue. Thus, Formula II compounds includewithout limitation linker groups having one or more carboxylic acidgroups, methylene carboxylic acid (acetyl) groups, substituted orunsubstituted aryl groups (e.g., benzyl or naphthyl groups), hydroxyl,or amino groups pendant to the linker.

Depending on whether the Formula II compounds are to be used as radioimaging agents or radio pharmaceuticals, different radionuclides may becomplexed to the compounds. Illustrative of suitable radionuclides arethose selected from the group consisting of ¹¹¹In, ⁹⁰Y, ⁶⁸Ga, ⁶⁴Cu¹⁵³Gd, ¹⁵⁵Gd, ¹⁵⁷Gd, Fe and ¹⁷⁷Lu. Illustrative compounds of Formula IIinclude, but are not limited to those shown in Table 2.

FIGS. 1A and 1B illustrate results of a bio-distribution study in LNCapxenograft mice of a GUG-DOTA-¹⁷⁷Lu complex (compound (A)) and aGUL-DOTA-¹⁷⁷Lu complex (compound (B)) according to Formula II.

As illustrated by the bar graphs, both compounds (A) and (B) concentrateto a greater extent in the kidneys than LNCap tumor cells at 4 hourspost administration. However, at 24 hours and 96 hours postadministration, the concentration is greater in LNCap tumor cells thankidney for both compounds. In fact, there was a significant reduction inthe concentration of both compounds in kidney at these later timeintervals. These results suggest that while the compound does accumulatein kidney soon after administration to LNCap tumor cell bearing mice,the accumulated compound is rapidly cleared from the body postadministration. In contrast, the inventive compounds accumulate withintumor cells with only a slight decrease in intratumoral concentrationobserved after 96 hours. Taken together, these results illustrate thegreater affinity of radionuclide complexes of Formula II compounds toselectively target and bind to LNCap tumor cells.

The compounds of Formula I or Formula II were screened in a humanprostate cancer cell binding assay using PSMA positive (+), LnCap cells.The results of this screening demonstrated to us whether the compoundsexhibited specific binding to PSMA (+) cells. Compounds that exhibitedspecific binding to PSMA (+) cells where further evaluated in acompetitive binding assay against the known inhibitor of PSMA,N—[N—[(S)-1,3-dicarboxypropyl]carbamoyl]-S-3-iodo-L-tyrosine (DCIT), andIC₅₀ values were calculated.

Briefly, LNCaP and PC3 human prostate cancer cells were obtained fromAmerican Type Culture Collection, Rockville, Md. LNCaP cells weremaintained in RPMI-1640 medium supplemented with 10% fetal bovine serum(FBS). Binding of the radiolabeled compound and competition with coldderivatives to LNCaP cells was performed according to published methods.Cells were plated in 12-well plates at approximately 4×10⁵ cells/welland incubated for 48 hours in a humidified incubator at 37° C./5% carbondioxide prior to addition of compound. Solutions of the Formula I orFormula II compounds were prepared and diluted in serum-free cellculture medium containing 0.5% bovine serum albumin (BSA) in combinationwith 3 nM ¹²³I DCIT (known inhibitor). Total binding was determined byincubating ¹²³I-DCIT without test compound. Plates were incubated atroom temperature for 1 hour. Cells were removed from the plates andtransferred to eppendorff tubes. Samples were microcentrifuged for 15seconds at 10K×g. The medium was aspirated and the pellet was washedtwice by dispersal in fresh assay medium followed bymicrocentrifugation. Cell binding of ¹²³I DCIT was determined bycounting the cell pellet in an automated gamma counter. Nonspecificbinding was determined as the counts associated with the cells afterincubating with 2 uM nonradiolabeled compound or2-phosphonomethyl-pentanedioic acid (PMPA). Table 3 illustrates the IC₅₀values of representative Formula II complexes.

TABLE 1 Complex IC₅₀ (nM) Lu-MIP-1512 23 Lu-MIP-1523 54 Lu-MIP-1530 21Lu-MIP-1531 28 Lu-MIP-1545 10 Lu-MIP-1546 15 Lu-MIP-1550 22 Lu-MIP-154877 Lu-MIP-1526 78 Lu-MIP-1519 12

Compounds of Formula I compounds or their pharmaceutically acceptablesalts, esters or solvates include:

Formula I compounds also comprise a first terminal group and a secondterminal group that are connected using a linker or spacer. The firstterminal group is a tripeptide comprising a glutamic-urea-lysine (GUL),or glutamic-urea-glutamic (GUG) moiety (see above), while the secondterminal group comprises a chelator such as moieties selected from

which may be complexed with a radionuclide.

For Formula I compounds each of X an Y in the first terminal group areeach independently (CHR¹)_(m) or C(O). When X is (CHR¹)_(m) Formula Icompounds are GUL analogs when m is 2. However, subscript “m” can be anyinteger from 0 to 6, both values inclusive. Alternatively, when X is acarbonyl (—C(O)—), inventive compounds comprising the GUG recognitionmotif are obtained.

Formula I and II compounds are candidate therapeutics for the treatmentand diagnosis of prostate cancer. The present inventors have found thatthe chemical nature and size of the linker effects affinity of Formula Iand Formula II compounds for PSMA expressed on the surface of prostatecancer cells. The present inventors used structure-activityrelationships to study (a) the correlation between linker size PSMAaffinity, and (b) to study the contribution of polar groups within thelinker region on PSMA binding.

For instance, the inventors found that using a aminohexanoic acid spacerto link the GUL recognition element to a DOTA-indium chelate gave aFormula I compound (1) that showed moderate activity for PSMA (IC₅₀=175nM).

The introduction of an amino group, such as the use of lysine to linkthe recognition motifs to DOTA, further reduced binding affinity. Thus,substitution of the aminohexanoic acid spacer with a lysine spacer gavecompound (2) which showed increased aqueous solubility but a two-foldreduced the affinity for PSMA (IC₅₀=443 nM).

It was further observed that the non-metalated Formula I compoundsshowed increased affinity for PSMA when compared to the correspondingradinuclide complexes.

Without ascribing to any particular theory, the inventors believe thatthe increased affinity of non-metalated Formula I compounds stems fromtheir reduced steric bulk and/or due to the additional bindinginteractions that occur between PSMA and the free carboxylic acid groupsof DOTA. In the radionuclide complex, however, the carboxyl groups ofDOTA are involved in metal coordination interactions and are notavailable, therefore, for interaction with appropriately positionedamino acid residues of PSMA.

To evaluate the percent contribution (a) or (b) to the overall decreasein binding affinity of Formula I compounds to PSMA the present inventorstested the affinity of the technetium-99m complex with DOTA for PSMA andcompared the IC₅₀ value for this complex to the correspondingnon-metallated compound. Decreased binding affinity was observed for theTechnitium-99m complex which suggests that the observed loss in bindingaffinity for the metal complex species, most likely is due to a loss inbinding interactions that occur between PSMA and the free carboxylicacid groups of DOTA.

According to one aspect,

represents the linker moiety of Formula I compounds and its metalcomplex with radionuclides. Thus, in one embodiment substituent W can bea H, or —(CH₂)_(p)—U. When W is —(CH₂)_(p)—U, p is an integer havingvalue of 0, 1, 2, 3, 4, 5, or 6, U is hydroxyl (—OH), —OR, —COOR orNR⁴R⁵. For instance, W can be —CH₂—COOH (acetate) group or an alkylester of acetate, for example, a methyl ester, ethyl ester, propylester, or t-butyl ester.

For Formula I compounds, L can be is —C(O)—(C₁-C₁₀)alkylene,—[C(O)—(CH(Z)_(d))—NH]_(j)NR²R³, —C(O)—(CHR¹)—(CH₂)_(p)—U—,—(C₅-C₁₄)aryl-(C₁-C₁₀)alkylene, R⁶O-benzylene,—(C₅-C₁₄)heteroaryl-(C₁-C₁₀)alkylene,[C(O)—CH(Z)_(d)—NH]_(t)—C(O)—(CHR¹)_(m)—(CH₂)_(p)—U, or—C(O)—[(CH₂)_(p)—V]_(n)—(CH₂)_(q)—C(O)—U.

T is H, —(C₁-C₁₀)alkylene, RC(O)—(C₁-C₁₀)alkylene,NR²R³—(C₁-C₁₀)alkylene, —(C₅-C₁₄)heteroaryl-(C₁-C₁₀)alkylene or—(C₅-C₁₄)aryl-(C₁-C₁₀)alkylene. V is —NH—, —NR²— or —NR²R³, while Z is—(CH₂)_(p)—COOH or —(CH₂)_(p)—NR²R³. For Formula I compounds, groups R,R^(a) and R^(b) are each independently —H, —OH, —(C₁-C₁₀)alkyl,—O(C₁-C₁₀)alkyl, or NHR² and R¹ is hydrogen or —NH₂. Groups R², R³, R⁴and R⁵ are each independently H, a bond, (C₁-C₁₀)alkylene, F, Cl, Br, I,C(O), C(S), —C(S)—NH-benzyl-, —C(O)—NH-benzyl-, —C(O)—(C₁-C₁₀)alkylene,—(CH₂)_(p)—NH—C(O)—(CH₂)_(p)—, —(CH₂—CH₂)_(t)—NH—C(O)—(CH₂)_(p)—,—(CH₂)_(p)—COR, —(CH₂)_(p)—C(O)NH—C[(CH₂)_(p)—COR]₃, —C[(CH₂)_(p)—COR]₃,or —(CH₂)_(p)—(C₅-C₁₄)heteroaryl.

For compounds according to Formula I, moreover, any aryl, heteroaryl, orcycloalkyl may be optionally substituted with 1, 2, or 3 substituentgroups such as —(C₁-C₁₀)alkyl, —(C₁-C₁₀)haloalkyl, —(C₁-C₁₀) aminoalkyl, —(C₁-C₁₀)hydroxyalkyl, —(CH₂)_(p)—C(O)—U and —(C₃-C₈)cycloalkyl.

In one embodiment, L is —(C₅-C₁₄)aryl-(C₁-C₁₀)alkylene and T is—(C₅-C₁₄)heteroaryl-(C₁-C₁₀)alkylene. In such embodiments L may be asubstituted benzyl, for example, R⁶O-benzylene where R⁶ is defined as—O(CH₂)_(p)—(C₅-C₁₄)heteroaryl-(CH₂)_(p)—U. Illustrative heteroarylsinclude without limitation imidazole, pyridine, 1,2,3-triazole,1,2,4-triazole, oxazole, and oxadiazole groups. L, for instance, can bea moiety represented by the following chemical structure:

The heteroaryl moiety of substituent T can be the same as L, ordifferent from L. In one embodiment T can be a chemical moietyrepresented by the following structure:

In one aspect, a compound of Formula I has the following structure:

Compound 3 (IC₅₀=46 nM), which utilized a dicarboxyimidazolefunctionalized linker binds to PSMA with an affinity that is almost aten-fold greater than the affinity of compound 1 having a amino-hexanoicacid linker shown above.

Compounds in accordance with the present invention can also utilizeethylenediaminetetraacetic acid (EDTA) to link DOTA to theGlutamate-urea-Lysine (GUL) and Glutamate-urea-Glutamate (GUG)recognition sequences.

Additionally, each EDTA group provides two free carboxylic acids whichare believed to increase renal clearance by improving aqueous solubilityand thus, reducing overall exposure of Formula I compounds to thekidneys. The EDTA linker is proposed to promote tighter binding ofinventive compounds to PSMA. Without being bound by theory, it isbelieved that the two free carboxylic acid groups on each EDTA in thelinker can participate in binding interactions with amino acid residuesof PSMA, thus, promoting the binding of Formula I compounds to thisprotein. Accordingly, radionuclide complexes of Formula I compoundshaving an EDTA linker will exhibit enhanced binding to PSMA, especiallywhen compared to compounds having an alkyl linker or a lysine linker.

To further explore whether the position of polar groups along the linkerchain affect binding of Formula I compounds to PSMA, compounds weresynthesized in which the linker is an appropriately functionalized alkylchain having a defined number of methylene groups is tethered to a GULor GUG motif at one end and one or more EDTA moieties are attached tothe opposite end of the alkyl chain.

According to this embodiment, substituent W is hydrogen; subscript k isan integer from 0 to 6, for example, 4, 5, or 6, substituent T is H andL is —C(O)—[(CH₂)_(p)—V]_(n)—(CH₂)_(q)—C(O)—U. In one embodiment, V is—NR²R³, R² is H and R³ is R—C(O)—(C₁-C₁₀)alkylene, for example, amethylene-COOH (—CH₂COOH) group, or an ethylene-COOH group. U is NR⁴R⁵with substituent R⁴, in one embodiment, being H and R⁵ being a—(CH₂)_(p)—NH—C(O)—(CH₂)_(p)— group. An illustrative Formula I compoundthat comports with the above definition is illustrated below:

The above class of Formula I compounds were high affinity ligands ofPSMA. Structure-activity studies indicated that the affinity of FormulaI compounds for PSMA increased for those compounds having carboxylicacid groups pendant to the linker. These observations support a role forpoly-aspartate or poly-glutamate based linkers. In one embodiment of theinvention, therefore, a series of compounds having varying number ofaspartate units, or glutamate units in the linker between the PSMArecognition sequence GUL or GUG and the chelator DOTA were synthesized.Typically, a series of four, five or six aspartatic acid residues orglutamic acid residues are used as the linker However, the number ofaspartic acid or glutamic acid residues in the linker can be from tworesidues to about 15 residues. A linker including a mixture of asparticacid and glutamic acid residues, such as alternating aspartic acid andglutamic acid residues may also be used in the compounds.

Binding studies for compounds of Formula I having aspartic acid,glutamic acid, or a mixture of aspartic acid and glutamic acid residuesin the linker showed that the free carboxylic acid groups of theseresidues may be participating in binding interaction with the PSMAprotein which results in enhanced affinity of these compounds for PSMA.Additionally, poly-glutamic acid is a substrate for PSMA. Thus, FormulaI compounds having a poly-glutamic acid linker may show increasedbinding affinity for PSMA. A Formula I compound having a poly-asparticacid or poly-glutamic acid linker is the following compound having fiveaspartate or glutamate residues between the GUL o GUG PSMA recognitionmoiety and the radionuclide chelator DOTA.

In yet another embodiment, Formula I compounds are provided having ahybrid linker made up of an aminohexanoic acid group and a lysinedipeptide structurally depicted below.

As shown above, the ε-amino of the side chains of the two lysine groupsare being used to tether the chelators SAAC II and DOTA. Based on theresults from experiments aimed at improving the pharmacokinetic profileof small molecules directed to PSMA and other protein targets implicatedin disease processes, the inventors have observed that the conjugationof SAAC II improved tissue distribution, renal clearance, most likely byimproving the aqueous solubility of the small molecule therapeutics andimaging agents.

Again, without being bound by theory, it is believed that theintroduction of CIM, TIM, or HIM SAAC II chelators in the linker betweenGUL or GUG PSMA recognition moities and DOTA should improve thepharmacokinetics of tissue distribution and renal clearance of Formula Icompounds. Indeed, inventive compounds and their metal complex having aSAAC II group in the linker showed improved aqueous solubility, goodrenal clearance and exhibited a strong affinity for PSMA protein onprostate cancer cells.

Examples of chemical groups having one or more carboxylic acid moietiesand that are suitable for incorporation into the linker region ofFormula I compounds include without limitation, those illustrated below,such as CIM, TIM and HIM.

When the chemical group providing the one or more carboxylic acid moietyin the linker is

each R′″ can independently be

The linker includes at least two carboxyl moieties, each having aformula —CO₂J. Each J, moreover, may be the same or different and isindependently selected from H, (C₁-C₆)lower alkyl, and apharmaceutically acceptable organic or inorganic salt.

For formula I compounds, D is a chelator group, for instance a groupsuch as DOTA, NOTA H₃[(sal)₃ TETA], H₂[(sal)₂ TETA], H₃[(5-MeOsal)₃TAME], DTPA, or HBED which are graphically represented by the followingstructures

In some embodiments D is a non-metallated2,2′,2″,2′″-(1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrayl)tetraaceticacid (DOTA), while in other embodiments D can be a non-metallatedchelator based on the structures exemplified above.

In other embodiments, D can be a metal complex formed by thecomplexation of a radionuclide with DOTA, NOTA or HBED as shown below.

Alternatively, D is a metal complex formed by the complexation of anappropriate radionuclide with the following metal chelators.

For inventive compounds according to Formula I, subscripts d, j, k, m,n, p and t are each independently an integer between 0 and 6. Forinstance, subscripts d, j, k, m, n, p and t can each independently be 0,1, 2, 3, 4, 5, or 6. When aryl, heteroaryl, or cycloalkyl substituentgroups are present in a Formula I compound, these substituent groups canoptionally be substituted by 1, 2, or 3 other substituent groupsselected from the group consisting of —(C₁-C₁₀)alkyl,—(C₁-C₁₀)haloalkyl, —(C₁-C₁₀) aminoalkyl, —(C₁-C₁₀)hydroxyalkyl,—(C₁-C₁₀)alkylene-C(O)—U, and —(C₃-C₈)cycloalkyl.

Depending on whether the inventive Formula I compounds are to be used asradio imaging agents or radio pharmaceuticals different radionuclidesare complexed to DOTA. Illustrative radionuclides include, for example¹¹¹In, ⁹⁰Y, ⁶⁸Ga, ¹⁷⁷Lu, ^(99m)Tc, ⁶⁴Cu, ¹⁵³Gd, ¹⁵⁵Gd, ¹⁵⁷Gd, and Fe.According to one aspect of this invention, the radionuclide is ¹¹¹In,⁹⁰Y, ⁶⁸Ga, ⁶⁴Cu, ¹⁵³Gd, ¹⁵⁵Gd, ¹⁵⁷Gd, Fe, or ¹⁷⁷Lu.

Based on the above described SAR study, Formula I compounds having oneor more carboxyl groups, or a SAAC II group in the linker between a GULor GUG recognition moiety and the chelator DOTA are potent inhibitors ofPSMA, with IC₅₀ values in the low nanomolar range. These compounds alsoshowed improved aqueous solubility which accounts, at least in part, fortheir improved tissue distribution and renal clearance.

FIG. 2 illustrates results of a bio-distribution study in LNCapxenograft mice using a GUL-DOTA-¹¹¹In complex and a hydrophobicaminohexanoic acid linker. As illustrated by the bar graph, the testcompound MIP-1450 concentrates in the kidney, that is, shows high kidneyuptake and poor uptake in LNCap tumor cells. The inventors hypothesizethat the low biodistribution of MIP-1450 LNCap tumor cells may be due tothis compounds low affinity for PSMA expressed on the surface of LNCapcells. As stated above, it was unexpectedly that presence of carboxylicacid groups in the linker region increased affinity of Formula Icompounds for PSMA. This increase in binding affinity is due, at leastin part to additional cooperative binding interactions of the freecarboxylic acid groups with amino acid residues of PSMA. Illustrative ofFormula I compound-radionuclide complexes that have one or morecarboxylic acid groups as part of the linker group include withoutlimitation the following compounds:

While the structures above do not illustrate pharmaceutically acceptablesalts and/or solvates of the inventive compounds; it is within the scopeof the present invention to encompass pharmaceutically acceptable saltforms and/or solvates. In some embodiments, the chelator group, forexample, the DOTA group is not complexed with a radionuclide. In oneembodiment, therefore, when DOTA is un-complexed the carboxylic acidgroups of the DOTA group can be in the form of a free acid, or in theform of a salt. The free carboxylic acid groups can also be esterifiedto obtain the prodrug form of Formula I compounds. Suitable esterprodrugs include various alkyl esters, including saturated andunsaturated C₈ to C₁₈ fatty acids.

When Formula I and Formula II compounds and their radionuclide complexeshave one or more chiral centers the present invention encompasses bothenantiomers, as well as all of the diasteroisomers. Moreover, both L andD-forms of the natural amino acids can be used for synthesizing theFormula I and Formula II compounds. That is, the present inventionencompasses stereoisomers, tautomers, and prodrugs of Formula I andFormula II compounds.

Pharmaceutical Formulations

As noted above, complexes of the compounds according Formula I orFormula II may contain one or more radionuclides which are suitable foruse as radio-imaging agents or as therapeutics for the treatment ofrapidly proliferating cells, for example, PSMA expressing prostatecancer cells. Accordingly, in one embodiment, a pharmaceuticalcomposition is provided including a complex that includes a metal and acompound of Formula I or Formula II, a salt, solvate, stereoisomer, ortautomer thereof, and a pharmaceutically acceptable carrier.

In general, metal complexes of a Formula I or a Formula II compound orpharmaceutical compositions thereof, may be administered orally, or viaa parenteral route, usually by injection. Parenteral routes include, butare not limited to, intravenous, intramuscular, intraarterial,intrathecal, intracapsular, intraorbital, intracardiac, intradermal,intraperitoneal, transtracheal, subcutaneous, subcuticular,intraarticulare, subcapsular, subarachnoid, intraspinal and intrasternalinjection and infusion. In some embodiments, the compound, orpharmaceutical composition thereof, is administered orally. Suchcompositions may take the form of tablets, pills, capsules, semisolids,powders, solutions, suspensions, elixirs, aerosols, or any otherappropriate compositions.

According to another aspect, a pharmaceutical composition is provided,which is suitable for in vivo imaging and radiotherapy. Suitablepharmaceutical compositions may contain a radio imaging agent, or aradiotherapeutic agent that has a radionuclide either as an element,i.e. radioactive iodine, or a radioactive metal chelate complex of thecompound of Formula I or Formula II in an amount sufficient for imaging,together with a pharmaceutically acceptable radiological vehicle. Theradiological vehicle should be suitable for injection or aspiration,such as human serum albumin; aqueous buffer solutions, e.g.,tris(hydromethyl)aminomethane (and its salts), phosphate, citrate,bicarbonate, etc; sterile water; physiological saline; and balancedionic solutions containing chloride and or dicarbonate salts or normalblood plasma cations such as calcium, potassium, sodium, and magnesium.

The concentration of the imaging agent or the therapeutic agent in theradiological vehicle should be sufficient to provide satisfactoryimaging. For example, when using an aqueous solution, the dosage isabout 1.0 to 50 millicuries. The actual dose administered to a patientfor imaging or therapeutic purposes, however, is determined by thephysician administering treatment. The imaging agent or therapeuticagent should be administered so as to remain in the patient for about 1to 24 hours, although both longer and shorter time periods areacceptable. Therefore, convenient ampoules containing 1 to 10 mL ofaqueous solution may be prepared.

Imaging may be carried out in the normal manner, for example byinjecting a sufficient amount of the imaging composition to provideadequate imaging and then scanning with a suitable machine, such as agamma camera. In certain embodiments, a method of imaging a region in apatient includes the steps of: (i) administering to a patient adiagnostically effective amount of a compound complexed with aradionuclide; exposing a region of the patient to radiation; and (ii)obtaining an image of the region of the patient. In certain embodimentsof the region imaged is the head or thorax. In other embodiments, thecompounds and complexes of Formula I or Formula II target the PSMAprotein.

Thus, in some embodiments, a method of imaging tissue such as spleentissue, kidney tissue, or PSMA-expressing tumor tissue is providedincluding contacting the tissue with a complex synthesized by contactinga radioactive metal and a Formula I compound or a Formula II compound.

In another aspect, a method of imaging a region in a patient is providedincluding administering to a patient a diagnostically effective amountor a therapeutically effective amount of a Formula I compound complexedto a metal or a Formula II compound, complexed to a metal, or apharmaceutically acceptable salt or solvate, and obtaining an image ofthe region of the patient. The metal used to form the complex is aradionuclide selected from ¹¹¹In, ⁹⁰Y, ⁶⁸Ga, ⁶⁴Cu ¹⁵³Gd, ¹⁵⁵Gd, ¹⁵⁷Gd,Fe or ¹⁷⁷Lu.

The amount of a Formula I or Formula II compound, or a formulationcomprising a complex of a metal and a compound according to Formula I orFormula II, or its salt, solvate, stereoisomer, or tautomer that isadministered to a patient depends on several physiological factors thatare routinely used by the physician, including the nature of imaging tobe carried out, tissue to be targeted for imaging or therapy and thebody weight and medical history of the patient to be imaged or treatedusing a radiopharmaceutical.

Accordingly in another aspect, the invention provides a method fortreating a patient by administering to a patient a therapeuticallyeffective amount of a Formula I or Formula II compound complexed to aradionuclide, or a pharmaceutically acceptable salt or solvate of thecomplex to treat a patient suffering from a cell proliferative diseaseor disorder. Specifically, the cell proliferative disease or disorder tobe treated using a radiopharmaceutical in accordance with this inventionis a cancer, for example, prostate cancer.

The present invention, thus generally described, will be understood morereadily by reference to the following examples, which are provided byway of illustration and are not intended to be limiting of the presentinvention.

EXAMPLES General Synthetic Methods

General procedure for complexation of the compounds with a metal. Asexemplified herein, indium is used as the metal. However, as is to beunderstood, similar synthetic procedures may be followed using the othermetals described herein to complex with the compounds of Formula I.Therefore, while indium may be specifically shown in various examples,it is understood to include Y, Ga, Lu complexes as well. Additionally,it is to be understood that various isotopes of these elements may becomplexed, for example, ¹¹¹In, ⁹⁰Y, ⁶⁸Ga, ⁶⁴Cu, or ¹⁷⁷Lu.

General Experimental Conditions for the Formation of the IndiumComplexes

The indium complexes of the compounds of Formula I are convenientlyisolated from the reactions that involve contacting commerciallyavailable InCl₃ with a compound of Formula I. Briefly, the appropriatecompound of Formula I (10⁻⁶ M-10⁻⁴ M) in an equal volume mixture of 1:1acetonitrile and phosphate buffer is contacted with InCl₃ in a sealedvial. The reaction mixture is allowed to heat at 100° C. for 30 to 45minutes. Upon cooling, the reaction was analyzed for purity viareverse-phase high pressure liquid chromatography (RP-HPLC) and ifrequired can be purified using RP-HPLC or C18 Sep Pak columns. Theaverage yield of the desired product following purification is in therange from about 20% to about 99%. The radiochemical purity (RCP), afterHPLC purification, however, was consistently ≧95%. for the “carrierfree” products. Although initial results demonstrated radiolabeling atconcentrations as low as 10⁻⁶ M, the radiochemical yield (RCY) at thisconcentration of reagents was ≦80%. To achieve a RCY greater than 95%,the reaction temperature and concentration of reagents in the reactionmixture were increased to 10⁻⁴ M.

A similar synthetic strategy was used to incorporate otherradionuclides. Moreover, the introduction of a radionuclide can be priorto deprotection of a Formula I compound, or after deprotecting a FormulaI compound.

Synthesis of Exemplary Formula I & Formula II Compounds

A. Scheme 1 is an illustration of the general synthetic route forGUL-HEX-EDTA-DOTA and GUG-HEX-EDTA-DOTA analogs.

The target compound is obtained using the t-butyl ester of GUL or GUG (4and 5 respectively) as starting materials. In the first step, acarboxybenzyloxy (Cbz)-protected aminohexanoic acid is reacted with GULto afford protected intermediate (6). If GUG is used as the recognitionmoiety, however, GUG is contacted with a Cbz-protected diaminohexane toafford protected intermediate (7). After removal of the Cbz protectinggroups by catalytic hydrogenation, intermediates (6) and (7) werebrought in contact with EDTA dianhydride followed contact with thecommercially available protected DOTA derivative 8. Subsequentdeprotection of the t-butyl ester groups afforded the desired EDTA-DOTAanalogs 9 and 10. Complexation of 9 or 10 with the desired radioactiveor non-radioactive metal isotope gave the desired metal complexes M-(9)and M-(10)

B. Scheme 2 illustrates a general synthetic route for utilization ofaspartic acid (Asp) or glutamic acid (Glu) linkers between the PSMArecognition sequence and the DOTA chelator.

In this series two, three, four, five, or six Asp or Glu residues mayserve as the pharmacokinetic modifying linker. The synthesis includescontacting GUL (intermediate 4), with an appropriately protectedaspartic acid or glutamic acid residue, followed by removal of the amineprotecting group and further contact with a second protected asparticacid or glutamic acid residue. The above steps of addition anddeprotection can be carried out sequentially until the desired number ofaspartic acid or glutamic acid residues are attached to obtain anappropriately sized linker.

In Scheme 2 above, two aspartic acid or glutamic acid residue is presentin the linker. Thus, deprotection of the Cbz protecting group of thesecond aspartic acid or glutamic acid residue gave compounds 12 and 13.Conjugation of 12 or 13 with the commercially available activated DOTAderivative 14 followed by deprotection of the t-butyl ester protectinggroups gave 15 and 16. Complexation of 15 or 16 with the desiredradioactive or non-radioactive metal isotope was straightforward andresulted in the desired metal complexes M-(15) and M-(16). The synthesisof analogs having three, four, five, six or more aspartic acid orglutamic acid residues proceeds in a manner analogous to the onedescribed above for the di-aspartic acid or di-glutamic acid linker.

Thus, using intermediates 12 and 13 as starting materials and repeatingthe coupling deprotection sequence afforded the desired analogs 17, 18,19 and 20. Deprotection of the t-butyl ester protecting groups followedby complexation with the desired radioactive or non-radioactive metalisotope gave the desired metal complexes M-(17), M-(18), M-(19) andM-(20).

C. Scheme 3 illustrates the general synthetic route for including achelator group on the pharmacokinetic modifying linker.

The incorporation of chelator groups on the pharmacokinetic modifyinglinker proceeds in a manner analogous to the ones described above.Briefly, the GUL-alkylene intermediate having a free amino group (6 or7) is contacted with Fmoc protected derivative 21 (CIM), 22 (TIM) or 23(HIM) under standard peptide coupling conditions to afford the protectedintermediates 24-29. These intermediates are then coupled to DOTA usingsynthetic protocols described above. The resultant compounds (30-35) arecomplexed with the desired radionuclide to afford the DOTA metalcomplexes M-(30)-M-(35).

D. Schemes 4, 5 and 6 illustrate methods for synthesizingGUL-SCN-Bn-DOTA compounds and their metal complexes.

Briefly GUL conjugates were prepared from the known protectedintermediate (S)-di-tert-butyl2-(3-((S)-6-amino-1-(tert-butoxy)-1-oxohexan-2-yl)ureido)pentanedioate(GUL-(OtBu)₃). Standard amide bond formation (EDCI, HOBt, DIPEA) withCbz-protected amino acids followed by deprotection of the Cbz group byhydrogenolyis using Pd—C and ammonium formate gave the desired GULmoiety. The sequence can be repeated with additional Cbz-protected aminoacids if desired. Linear amino acids such as N-Cbz-6-hexanoic acid wereused in one embodiment as the linker for conjugation to the DOTAchelator. Deprotection of the t-butyl ester protecting groups with TFAfollowed by conjugation to commercially available SCN-Bn-DOTA and HPLCpurification afforded the final pure ligand conjugates.

Complexation of the GUL-SCN-Bn-DOTA conjugate with cold lutetium wasaccomplished by warming an aqueous solution of the GUL-SCN-Bn-DOTAconjugate (MIP1523) and LuCl₃ for 30 minutes followed by lyophilizationto afford the desired(10S,17S,21S)-10-(2-carboxyethyl)-8,11,19-trioxo-1-((4-((1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,9,12,18,20-pentaazatricosane-17,21,23-tricarboxylateLu complex.

The protocol illustrated in Scheme 5 above was used to synthesize(10S,17S,21S)-10-(4-fluorobenzyl)-8,11,19-trioxo-1-((4-((1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,9,12,18,20-pentaazatricosane-17,21,23-tricarboxylicacid and its lutetium complex.

The protocol illustrated in Scheme 6 above was used to synthesize(10S,13S,20S,24S)-13-(2-carboxyethyl)-10-(4-fluorobenzyl)-8,11,14,22-tetraoxo-1-((4-((1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,9,12,15,21,23-hexaazahexacosane-20,24,26-tricarboxylicacid and its lutetium complex.

E. Schemes 7, 8 and 9 illustrate a route for synthesizingGUG-SCN-Bn-DOTA compounds and their metal complexes. The GUG-SCN-Bn-DOTAcompounds and their metal complexes were synthesized using(S)-5-(tert-butoxy)-4-(3-((S)-1,5-di-tert-butoxy-1,5-dioxopentan-2-yl)ureido)-5-oxopentanoicacid (GUG-(OtBu)₃). Standard amide bond forming reagents, such as EDCI,HOBt, DIPEA were used to conjugate the side chain carboxylic acid of GUGto the amino group of aspartate methyl ester or other amines.

Deprotection of the methyl ester was effected by hydrolysis usingLiOH/MeOH gives t-butyl ester protected free acids which can be coupledto additional amino acids protected as their methyl esters or to a monoN-Boc-protected diaminoalkane. Deprotection of the t-butyl ester and Bocprotecting groups was carried out using a dichloromethan solution oftrifluoroacetic acid (TFA/DCM). Conjugation to commercially availableSCN-Bn-DOTA followed by HPLC purification afforded the final pure ligandconjugates. The complexation of the GUG-SCN-Bn-DOTA conjugates with coldlutetium was accomplished by warming an aqueous solution of LuCl₃containing the GUG-SCN-Bn-DOTA conjugate for 30 min followed bylyophilization to afford the pure desired Lu-complexes.

The protocol illustrated in Scheme 7 above was used to synthesize(11S,16S,20S)-11-(2-carboxyethyl)-10,13,18-trioxo-1-((4-((1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,9,12,17,19-pentaazadocosane-16,20,22-tricarboxylicacid and its lutetium complex.

The protocol illustrated in Scheme 8 above was used to synthesize(13S,17S)-10,15-dioxo-1-((4-((1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,9,14,16-tetraazanonadecane-13,17,19-tricarboxylicacid and its lutetium complex.

Example 9

The protocol illustrated in Scheme 9 above was used to synthesize(11S,16S,20S)-11-benzyl-10,13,18-trioxo-1-((4-((1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,9,12,17,19-pentaazadocosane-16,20,22-tricarboxylicacid and its lutetium complex.

Scheme 10 provides an exemplary route for conjugating a2,2′((1Z,11Z)-2,5,8,11-tetraazadodeca-1,11-diene-1,12-diyl)diphenolchelator group to a GUL-linker or GUG-linker moiety to obtain a FormulaI or Formula II compound.

Briefly, a 4-isocyanatobenzaldehyde will be contacted with a GUL-linkeror GUG-linker conjugate to provide the corresponding4-formylphenyl-1-thiourea. This moiety will then be contacted with thechelator to obtain the desired Formula I-chelator or Formula II-chelatorcompounds. The conjugation of the chelator group to a GUL-linker orGUG-linker moiety can be performed under reductive amination conditions.

Synthetic protocols schematically illustrated above were used tomanufacture other Formula I and Formula II compounds as furtherdescribed below.

Synthesis and Characterization Example 1(14S,18S)-1-(1-(2-(bis(carboxymethypamino)-2-oxoethyl)-1H-imidazol-2-yl)-8,16-dioxo-2-(4-((1-(3-(2-(4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecan-1-yl)acetamido)propyl)-1H-1,2,3-triazol-4-yl)methoxy)benzyl)-2,9,15,17-tetraazaicosane-14,18,20-tricarboxylicacid Indium complex (MIP-1445)

Step 1. 6-((4-(prop-2-yn-1-yloxy)benzyl)amino)hexanoic acid

A solution of 6-aminohexanoic acid (2.62 g, 20 mmol),4-(prop-2-yn-1-yloxy)benzaldehyde (0.80 g, 5.0 mmol) and acetic acid(0.50 mL) in DCE (50 mL) was heated at 80° C. for 60 min. The reactionmixture was cooled to 0° C., and treated with NaBH(OAc)₃ (2.11 g, 10mmol). The reaction was stirred at room temperature for 12 hours anddecomposed with water and then extracted with DCM. The organic layer wasdried and concentrated under reduced pressure to give a residue, whichwas purified using a Biotage SP4 and gradient elution of 5-50% methanolin DCM. The yield of the target compound6-((4-(prop-2-yn-1-yloxy)benzyl)amino)hexanoic acid was 62% (0.856 g).¹H NMR (400 MHz, DMSO-d₆): δ 7.19 (d, J=8.4 Hz, 2H), 6.86 (d, J=8.4 Hz,2H), 4.71 (s, 2H), 3.56 (s, 2H), 3.49 (s, 1H), 2.39 (t, J=7.0 Hz, 2H),2.00 (t, J=7.2 Hz, 2H), 1.41-1.19 (m, 6H); MS (ESI), 276.1 (M+H)⁺.

Step 2.6-(((1-(2-(bis(2-(tert-butoxy)-2-oxoethyl)amino)-2-oxoethyl)-1H-imidazol-2-yl)methyl)(4-(prop-2-yn-1-yloxy)benzyl)amino)hexanoicacid

A solution of 6-((4-(prop-2-yn-1-yloxy)benzyl)amino)hexanoic acid (0.715g, 2.60 mmol), tert-butyl2,2′-(2-(2-formyl-1H-imidazol-1-yl)acetylazanediyl)diacetate (0.99 g,2.60 mmol) and acetic acid (0.10 mL) in DCE (80 mL) at 0° C. was treatedwith NaBH(OAc)₃ (1.05 g, 5.0 mmol). The reaction mixture was stirred at0° C. for 30 min and at room temperature overnight and decomposed withwater and methanol. The reaction mixture was concentrated under reducedpressure to give a residue, and purified via Biotage SP4 silica gelcolumn to afford6-(((1-(2-(bis(2-(tert-butoxy)-2-oxoethyl)amino)-2-oxoethyl)-1H-imidazol-2-yl)methyl)(4-(prop-2-yn-1-yloxy)benzyl)amino)hexanoicacid (0.3313 g, 20%). ¹H NMR (400 MHz, DMSO-d₆): δ 11.90 (s, 1H), 7.17(d, J=8.4 Hz, 2H), 6.94 (s, 1H), 6.87 (d, J=8.4 Hz, 2H), 6.74 (s, 1H),5.02 (s, 2H), 4.72 (d, J=2.4 Hz, 2H), 4.24 (s, 2H), 3.94 (s, 2H), 3.48(s, 2H), 3.51 (s, 1H), 3.40 (s, 2H), 2.21 (t, J=7.2 Hz, 2H), 2.10 (t,J=7.4 Hz, 2H), 1.45-1.35 (m, 22H), 1.11-1.06 (m, 2H); MS (ESI), 641.3(M+H)⁺.

Step 3. (14S,18S)-tri-tert-butyl1-(1-(2-(bis(2-(tert-butoxy)-2-oxoethyl)amino)-2-oxoethyl)-1H-imidazol-2-yl)-8,16-dioxo-2-(4-(prop-2-yn-1-yloxy)benzyl)-2,9,15,17-tetraazaicosane-14,18,20-tricarboxylate

A solution of (S)-di-tert-butyl2-(3-((S)-6-amino-1-(tert-butoxy)-1-oxohexan-2-yl)ureido)pentanedioate(0.742 g, 1.52 mmol),6-(((1-(2-(bis(2-(tert-butoxy)-2-oxoethyl)amino)-2-oxoethyl)-1H-imidazol-2-yl)methyl)(4-(prop-2-yn-1-yloxy)benzyl)amino)hexanoicacid (0.244 g, 0.38 mmol), EDCI (0.290 g, 1.52 mmol), HOBt (0.051 g,0.38 mmol) and DIPEA (0.40 mL) in DCE (5.0 mL) was stirred at roomtemperature for 4 h. The solvent was evaporated to give a residue, whichwas purified by Biotage SP4 eluting with DCM/MeOH to give(14S,18S)-tri-tert-butyl1-(1-(2-(bis(2-(tert-butoxy)-2-oxoethyl)amino)-2-oxoethyl)-1H-imidazol-2-yl)-8,16-dioxo-2-(4-(prop-2-yn-1-yloxy)benzyl)-2,9,15,17-tetraazaicosane-14,18,20-tricarboxylate(0.3237 g, 77%) as a white solid. ¹H NMR (400 MHz, DMSO-d₆): δ 7.64 (t,J=5.4 Hz, 1H), 7.17 (d, J=8.4 Hz, 2H), 6.93 (s, 1H), 6.87 (d, J=8.8 Hz,2H), 6.74 (s, 1H), 6.26 (d, J=8.4 Hz, 1H), 6.22 (d, J=8.0 Hz, 1H), 5.02(s, 2H), 4.72 (d, J=2.0 Hz, 2H), 4.24 (s, 2H), 4.03-3.89 (m, 4H), 3.51(t, J=2.0 Hz, 1H), 3.48 (s, 2H), 3.39 (s, 2H), 2.95 (q, J=6.3 Hz, 2H),2.22-2.15 (m, 4H), 1.94 (t, J=7.4 Hz, 2H), 1.85-1.04 (m, 34H); MS (ESI),1111.6 (M+H)⁺.

Step 4. (14S,18S)-tri-tert-butyl2-(4-((1-(3-aminopropyl)-1H-1,2,3-triazol-4-yl)methoxy)benzyl)-1-(1-(2-(bis(2-(tert-butoxy)-2-oxoethyl)amino)-2-oxoethyl)-1H-imidazol-2-yl)-8,16-dioxo-2,9,15,17-tetraazaicosane-14,18,20-tricarboxylate

To a solution of (14S,18S)-tri-tert-butyl1-(1-(2-(bis(2-(tert-butoxy)-2-oxoethyl)amino)-2-oxoethyl)-1H-imidazol-2-yl)-8,16-dioxo-2-(4-(prop-2-yn-1-yloxy)benzyl)-2,9,15,17-tetraazaicosane-14,18,20-tricarboxylate(65 mg, 0.0586 mmol) and 3-azidopropan-1-amine (200 mg, 2.0 mmol) in THF(2.0 mL) and water (0.5 mL) was added copper powder (10 mg) and 1 NCuSO₄ (0.05 mL). The mixture was stirred at room temperature for 2 hunder nitrogen, diluted with DCM and washed with an aqueous saturatedsolution of EDTA. The solvent was evaporated under reduce pressure toafford a residue, which was purified by Biotage SP4 to afford(14S,18S)-tri-tert-butyl2-(4-((1-(3-aminopropyl)-1H-1,2,3-triazol-4-yl)methoxy)benzyl)-1-(1-(2-(bis(2-(tert-butoxy)-2-oxoethyl)amino)-2-oxoethyl)-1H-imidazol-2-yl)-8,16-dioxo-2,9,15,17-tetraazaicosane-14,18,20-tricarboxylate(17.5 mg, 25%). MS (ESI), 605.8 (M/2+H)′.

Step 5.((14S,18S)-1-(1-(2-(bis(carboxymethyl)amino)-2-oxoethyl)-1H-imidazol-2-yl)-8,16-dioxo-2-(4-((1-(3-(2-(4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecan-1-yl)acetamido)propyl)-1H-1,2,3-triazol-4-yl)methoxy)benzyl)-2,9,15,17-tetraazaicosane-14,18,20-tricarboxylicacid (MIP-1459)

A solution of (14S,18S)-tri-tert-butyl2-(4-((1-(3-aminopropyl)-1H-1,2,3-triazol-4-yl)methoxy)benzyl)-1-(1-(2-(bis(2-(tert-butoxy)-2-oxoethyl)amino)-2-oxoethyl)-1H-imidazol-2-yl)-8,16-dioxo-2,9,15,17-tetraazaicosane-14,18,20-tricarboxylate(17.5 mg, 0.0145 mmol),2,2′,2″-(10-(2-((2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)oxy)-2-oxoethyl)-1,4,7,10-tetraazacyclododecane-1,4,7-triyl)triaceticacid (30 mg, 0.60 mmol) and DIPEA (0.20 mL) in DMF (0.50 mL) was stirredat room temperature for 2 h. The solvent was evaporated to give aresidue, to which was added TFA (0.50 mL) and DCM (0.50 mL). The mixturewas stirred at rt for 4 h. The solvent was removed under a stream ofnitrogen to give a residue, which was purified by HPLC to yield MIP-1459(10 mg). MS (ESI), 659.0 (M/2+H)⁺.

Step 6. Synthesis of ((14S,18S)-tri-tert-butyl1-(1-(2-(bis(2-(tert-butoxy)-2-oxoethyl)amino)-2-oxoethyl)-1H-imidazol-2-yl)-8,16-dioxo-2-(4-((1-(3-(2-(4,7,10-tris(2-(tert-butoxy)-2-oxoethyl)-1,4,7,10-tetraazacyclododecan-1-yl)acetamido)propyl)-1H-1,2,3-triazol-4-yl)methoxy)benzyl)-2,9,15,17-tetraazaicosane-14,18,20-tricarboxylate(MIP-1459 t-butyl estert)

To a solution of (14S,18S)-tri-tert-butyl1-(1-(2-(bis(2-(tert-butoxy)-2-oxoethyl)amino)-2-oxoethyl)-1H-imidazol-2-yl)-8,16-dioxo-2-(4-(prop-2-yn-1-yloxy)benzyl)-2,9,15,17-tetraazaicosane-14,18,20-tricarboxylate(145 mg, 0.13 mmol), tri-tert-butyl2,2′,2″-(10-(2-((3-azidopropyl)amino)-2-oxoethyl)-1,4,7,10-tetraazacyclododecane-1,4,7-triyl)triacetate(59 mg, 0.090 mmol) in THF (5.0 mL) and water (1.0 mL) was added copperpowder (6.4 mg) and 1 N CuSO₄ (0.01 mL). The mixture was stirred at roomtemperature for overnight under nitrogen, diluted with EtOAc, washedwith an aqueous saturated solution of EDTA. The solvent was evaporatedunder reduce pressure to afford a residue, which was purified by BiotageSP4 to afford ((14S,18S)-tri-tert-butyl1-(1-(2-(bis(2-(tert-butoxy)-2-oxoethyl)amino)-2-oxoethyl)-1H-imidazol-2-yl)-8,16-dioxo-2-(4-((1-(3-(2-(4,7,10-tris(2-(tert-butoxy)-2-oxoethyl)-1,4,7,10-tetraazacyclododecan-1-yl)acetamido)propyl)-1H-1,2,3-triazol-4-yl)methoxy)benzyl)-2,9,15,17-tetraazaicosane-14,18,20-tricarboxylate(21.8 mg). MS (ESI), 883.2 (M/2+H)′.

Step 7.(14S,18S)-1-(1-(2-(bis(carboxymethyl)amino)-2-oxoethyl)-1H-imidazol-2-yl)-8,16-dioxo-2-(4-((1-(3-(2-(4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecan-1-yl)acetamido)propyl)-1H-1,2,3-triazol-4-yl)methoxy)benzyl)-2,9,15,17-tetraazaicosane-14,18,20-tricarboxylicacid Indium complex (MIP-1445)

A solution of ((14S,18S)-tri-tert-butyl1-(1-(2-(bis(2-(tert-butoxy)-2-oxoethyl)amino)-2-oxoethyl)-1H-imidazol-2-yl)-8,16-dioxo-2-(4-((1-(3-(2-(4,7,10-tris(2-(tert-butoxy)-2-oxoethyl)-1,4,7,10-tetraazacyclododecan-1-yl)acetamido)propyl)-1H-1,2,3-triazol-4-yl)methoxy)benzyl)-2,9,15,17-tetraazaicosane-14,18,20-tricarboxylate(21 mg, 0.012 mmol) in TFA (2.0 mL) and DCM (2.0 mL) was stirred at rtovernight. The solvent was removed under a stream of nitrogen to give acrude((14S,18S)-1-(1-(2-(bis(carboxymethyl)amino)-2-oxoethyl)-1H-imidazol-2-yl)-8,16-dioxo-2-(4-((1-(3-(2-(4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecan-1-yl)acetamido)propyl)-1H-1,2,3-triazol-4-yl)methoxy)benzyl)-2,9,15,17-tetraazaicosane-14,18,20-tricarboxylicacid, (MIP-1459), which was dissolved in ammonium acetate (0.30 mL, 0.50N) solution in water (0.50 mL) with InCl₃ (10 mg). The reaction mixturewas heated at 95° C. for 1 h and was purified by HPLC to give theproduct (MIP-1445, (1 mg)). MS (ESI), 714.9 (M/2+H)⁺.

Example 2(14S,18S)-1-(1-(carboxymethyl)-1H-imidazol-2-yl)-8,16-dioxo-2-(4-((1-(3-(2-(4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecan-1-yl)acetamido)propyl)-1H-1,2,3-triazol-4-yl)methoxy)benzyl)-2,9,15,17-tetraazaicosane-14,18,20-tricarboxylicacid Indium complex (MIP-1470)

Step 1.6-(((1-(2-(tert-butoxy)-2-oxoethyl)-1H-imidazol-2-yl)methyl)(4-(prop-2-yn-1-yloxy)benzyl)amino)hexanoicacid

A solution of 6-((4-(prop-2-yn-1-yloxy)benzyl)amino)hexanoic acid(0.4125 g, 1.50 mmol), tert-butyl 2-(2-formyl-1H-imidazol-1-yl)acetate(0.315 g, 1.50 mmol) and AcOH (0.05 mL) in DCE (40 mL) at 0° C. wastreated with NaBH(OAc)₃ (0.636 g, 3.0 mmol). The reaction mixture wasstirred at 0° C. for 30 min and at room temperature for overnight anddecomposed with water and methanol. The reaction mixture wasconcentrated under reduced pressure to give a residue, which waspurified by Biotage SP4 over silica gel to afford6-(((1-(2-(tert-butoxy)-2-oxoethyl)-1H-imidazol-2-yl)methyl)(4-(prop-2-yn-1-yloxy)benzyl)amino)hexanoicacid (0.268 g, 38%). MS (ESI), 470.3 (M+H)⁺.

Step 2. (14S,18S)-tri-tert-butyl1-(1-(2-(tert-butoxy)-2-oxoethyl)-1H-imidazol-2-yl)-8,16-dioxo-2-(4-(prop-2-yn-1-yloxy)benzyl)-2,9,15,17-tetraazaicosane-14,18,20-tricarboxylate

A solution of (S)-di-tert-butyl2-(3-((S)-6-amino-1-(tert-butoxy)-1-oxohexan-2-yl)ureido)pentanedioate(0.480 g, 1.0 mmol),6-(((1-(2-(tert-butoxy)-2-oxoethyl)-1H-imidazol-2-yl)methyl)(4-(prop-2-yn-1-yloxy)benzyl)amino)hexanoicacid (0.220 g, 0.468 mmol), EDCI (0.191 g, 1.0 mmol), HOBt (0.135 g, 1.0mmol) and DIPEA (0.40 mL) in DCE (10.0 mL) was stirred at roomtemperature for 3 h. The solvent was evaporated to give a residue, whichwas purified by Biotage eluting with DCM/MeOH to give(14S,18S)-tri-tert-butyl1-(1-(2-(tert-butoxy)-2-oxoethyl)-1H-imidazol-2-yl)-8,16-dioxo-2-(4-(prop-2-yn-1-yloxy)benzyl)-2,9,15,17-tetraazaicosane-14,18,20-tricarboxylate(0.251 g, 57%). MS (ESI), 939.5 (M+H)⁺.

Step 3. (14S,18S)-tri-tert-butyl2-(4-((1-(3-aminopropyl)-1H-1,2,3-triazol-4-yl)methoxy)benzyl)-1-(1-(2-(tert-butoxy)-2-oxoethyl)-1H-imidazol-2-yl)-8,16-dioxo-2,9,15,17-tetraazaicosane-14,18,20-tricarboxylate

To a solution of (14S,18S)-tri-tert-butyl1-(1-(2-(tert-butoxy)-2-oxoethyl)-1H-imidazol-2-yl)-8,16-dioxo-2-(4-(prop-2-yn-1-yloxy)benzyl)-2,9,15,17-tetraazaicosane-14,18,20-tricarboxylate(250 mg, 0.266 mmol) and 3-azidopropan-1-amine (200 mg, 2.0 mmol) in THF(5.0 mL) and water (1.0 mL) was added copper powder (17 mg) and 1 NCuSO₄ (0.05 mL). The mixture was stirred at room temperature for 6 hrsunder nitrogen, diluted with DCM, washed with aqueous saturated solutionof EDTA. The solvent was evaporated under reduce pressure to afford aresidue, which was purified by Biotage SP4 to afford(14S,18S)-tri-tert-butyl2-(4-((1-(3-aminopropyl)-1H-1,2,3-triazol-4-yl)methoxy)benzyl)-1-(1-(2-(tert-butoxy)-2-oxoethyl)-1H-imidazol-2-yl)-8,16-dioxo-2,9,15,17-tetraazaicosane-14,18,20-tricarboxylate(158 mg, 57%) as a yellow oil. MS (ESI), 520.4 (M/2+H)⁺.

Step 4.(14S,18S)-1-(1-(carboxymethyl)-1H-imidazol-2-yl)-8,16-dioxo-2-(4-((1-(3-(2-(4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecan-1-yl)acetamido)propyl)-1H-1,2,3-triazol-4-yl)methoxy)benzyl)-2,9,15,17-tetraazaicosane-14,18,20-tricarboxylicacid (MIP-1469)

A solution of (14S,18S)-tri-tert-butyl2-(4-((1-(3-aminopropyl)-1H-1,2,3-triazol-4-yl)methoxy)benzyl)-1-(1-(2-(tert-butoxy)-2-oxoethyl)-1H-imidazol-2-yl)-8,16-dioxo-2,9,15,17-tetraazaicosane-14,18,20-tricarboxylate(148 mg, 0.143 mmol),2,2′,2″-(10-(2-((2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)oxy)-2-oxoethyl)-1,4,7,10-tetraazacyclododecane-1,4,7-triyl)triaceticacid (71 mg, 0.143 mmol) and DIPEA (0.30 mL) in DMF (3.0 mL) was stirredat room temperature for overnight. The solvent was evaporated to give aresidue, which was added TFA (3.0 mL) and DCM (3.0 mL). The mixture wasstirred at rt overnight. The solvent was removed under a stream ofnitrogen to give a residue, which was purified by HPLC to give MIP-1467(33.4 mg) as a white solid. MS (ESI), 601.4 (M/2+H)⁺.

Step 5.(14S,18S)-1-(1-(carboxymethyl)-1H-imidazol-2-yl)-8,16-dioxo-2-(4-((1-(3-(2-(4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecan-1-yl)acetamido)propyl)-1H-1,2,3-triazol-4-yl)methoxy)benzyl)-2,9,15,17-tetraazaicosane-14,18,20-tricarboxylicacid Indium complex (MIP-1470)

To a solution of(14S,18S)-1-(1-(carboxymethyl)-1H-imidazol-2-yl)-8,16-dioxo-2-(4-((1-(3-(2-(4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecan-1-yl)acetamido)propyl)-1H-1,2,3-triazol-4-yl)methoxy)benzyl)-2,9,15,17-tetraazaicosane-14,18,20-tricarboxylicacid (14.3 mg, 0.0119) and ammonium acetate (1.0 mL, 0.50 N) in water(2.0 mL) was added InCl₃ (9 mg). The reaction mixture was heated at 100°C. for 45 min and was purified by HPLC to give MIP-1470 (2.9 mg). MS(ESI), 657.2 (M/2+H)⁺.

Example 3(8S,15S,19S)-8-amino-2,9,17-trioxo-1-(4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecan-1-yl)-3,10,16,18-tetraazahenicosane-15,19,21-tricarboxylicacid Indium complex (MIP-1458)

Step 1. (8S,15S,19S)-tri-tert-butyl8-amino-2,9,17-trioxo-1-(4,7,10-tris(2-(tert-butoxy)-2-oxoethyl)-1,4,7,10-tetraazacyclododecan-1-yl)-3,10,16,18-tetraazahenicosane-15,19,21-tricarboxylate

A solution of (S)-di-tert-butyl2-(3-((S)-6-amino-1-(tert-butoxy)-1-oxohexan-2-yl)ureido)pentanedioate(0.048 g, 0.10 mmol),(S)-2-((((9H-fluoren-9-yl)methoxy)carbonyl)amino)-6-(2-(4,7,10-tris(2-(tert-butoxy)-2-oxoethyl)-1,4,7,10-tetraazacyclododecan-1-yl)acetamido)hexanoicacid (56 mg, 0.0607 mmol), EDCI (19 mg, 0.10 mmol), HOBt (13.5 mg, 0.10mmol) and DIPEA (0.10 mL) in DCM (5.0 mL) was stirred at roomtemperature for 2 hrs. The solvent was evaporated to give a residue,which was purified by Biotage eluting with DCM to 10% MeOH in DCM togive (5S,12S,16S)-tri-tert-butyl1-(9H-fluoren-9-yl)-3,6,14-trioxo-5-(4-(2-(4,7,10-tris(2-(tert-butoxy)-2-oxoethyl)-1,4,7,10-tetraazacyclododecan-1-yl)acetamido)butyl)-2-oxa-4,7,13,15-tetraazaoctadecane-12,16,18-tricarboxylate(115 mg) containing some impurity. MS (ESI), 697.0 (M+H)⁺.

To a solution of (5S,12S,16S)-tri-tert-butyl1-(9H-fluoren-9-yl)-3,6,14-trioxo-5-(4-(2-(4,7,10-tris(2-(tert-butoxy)-2-oxoethyl)-1,4,7,10-tetraazacyclododecan-1-yl)acetamido)butyl)-2-oxa-4,7,13,15-tetraazaoctadecane-12,16,18-tricarboxylate(115 mg) containing some impurity in DMF (0.30 mL) and piperidine (0.30mL) was stirred at rt for 1 hr. Solvents were evaporated under reducedpressure to give a residue, which was purified by Biotage eluting withDCM to 10% MeOH in DCM to give (8S,15S,19S)-tri-tert-butyl8-amino-2,9,17-trioxo-1-(4,7,10-tris(2-(tert-butoxy)-2-oxoethyl)-1,4,7,10-tetraazacyclododecan-1-yl)-3,10,16,18-tetraazahenicosane-15,19,21-tricarboxylate(64 mg, 90%) as a colorless oil. MS (ESI), 1171.6 (M+H)⁺.

Step 2.(8S,15S,19S)-8-amino-2,9,17-trioxo-1-(4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecan-1-yl)-3,10,16,18-tetraazahenicosane-15,19,21-tricarboxylicacid (MIP-1457)

A solution of ((8R,15S,19S)-tri-tert-butyl8-amino-2,9,17-trioxo-1-(4,7,10-tris(2-(tert-butoxy)-2-oxoethyl)-1,4,7,10-tetraazacyclododecan-1-yl)-3,10,16,18-tetraazahenicosane-15,19,21-tricarboxylate(64 mg) in TFA (1.0 mL) and DCM (1.0 mL) was stirred at rt forovernight. The solvent was removed under a stream of nitrogen to givecrude(8S,15S,19S)-8-amino-2,9,17-trioxo-1-(4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecan-1-yl)-3,10,16,18-tetraazahenicosane-15,19,21-tricarboxylicacid (57.9 mg). A small amount (9 mg) crude product was purified by HPLCto give pure(8S,15S,19S)-8-amino-2,9,17-trioxo-1-(4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecan-1-yl)-3,10,16,18-tetraazahenicosane-15,19,21-tricarboxylicacid (MIP-1457, (2.7 mg)) as a white solid. MS (ESI), 832.2 (M−H)⁻.

Step 3.(8S,15S,19S)-8-amino-2,9,17-trioxo-1-(4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecan-1-yl)-3,10,16,18-tetraazahenicosane-15,19,21-tricarboxylicacid Indium complex (MIP-1458)

To a solution of(8S,15S,19S)-8-amino-2,9,17-trioxo-1-(4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecan-1-yl)-3,10,16,18-tetraazahenicosane-15,19,21-tricarboxylicacid (18 mg) and ammonium acetate (0.50 mL, 0.50 N) in water (2.0 mL)was added InCl₃ (9 mg). The reaction mixture was heated at 100° C. for45 min and was purified by HPLC to give the titled product (MIP-1458,(4.0 mg)). MS (ESI), 946.4 (M+H)⁺.

Example 4 Synthesis of(16S,20S)-10,18-dioxo-1-((4-((1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,11,17,19-tetraazadocosane-16,20,22-tricarboxylicacid (MIP-1512)

Electrospray ionisation mass spectral analysis: [MS (ESI)]: (M+H)⁺=1013.

Example 5 Synthesis of(16S,20S)-10,18-dioxo-1-((4-((1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,11,17,19-tetraazadocosane-16,20,22-tricarboxylateLu complex (Lu-MIP-1512)

Electrospray ionisation mass spectral analysis: [MS (ESI)]: (M+H)⁺=1182.

Example 6

Synthesis of(10S,17S,21S)-10-(2-carboxyethyl)-8,11,19-trioxo-1-((4-((1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,9,12,18,20-pentaazatricosane-17,21,23-tricarboxylicacid (MIP-1523) was carried out as illustrated in Scheme 5 above

[MS (ESI)]: (M+H)⁺=1114.

Example 7

Synthesis of(10S,17S,21S)-10-(2-carboxyethyl)-8,11,19-trioxo-1-((4-((1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,9,12,18,20-pentaazatricosane-17,21,23-tricarboxylateLu complex (Lu-MIP-1523) was carried out as illustrated in Scheme 5above

[MS (ESI)]: (M+H)⁺=1285.

Example 8 Synthesis of(10S,17S,21S)-10-benzyl-8,11,19-trioxo-1-((4-((1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,9,12,18,20-pentaazatricosane-17,21,23-tricarboxylicacid (MIP-1530)

[MS (ESI)]: (M+H)⁺=1132.

Example 9 Synthesis of(10S,17S,21S)-10-benzyl-8,11,19-trioxo-1-((4-((1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,9,12,18,20-pentaazatricosane-17,21,23-tricarboxylate-Lucomplex (Lu-MIP-1530)

[MS (ESI)]: (M+H)⁺=1303 (M+H)⁺.

Example 10 Synthesis of(3S,7S,14S,17S)-14-benzyl-5,13,16-trioxo-17-(6-(3-(4-(((S)-1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)thioureido)hexanamido)-4,6,12,15-tetraazanonadecane-1,3,7,19-tetracarboxylicacid (MIP-1531)

[MS (ESI)]: (M+H)⁺=1261.

Example 11 Synthesis of(3S,7S,14S,17S)-14-benzyl-5,13,16-trioxo-17-(6-(3-(4-(((S)-1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)thioureido)hexanamido)-4,6,12,15-tetraazanonadecane-1,3,7,19-tetracarboxylateLu complex (Lu-MIP-1531)

[MS (ESI)]: (M+H)⁺=1432.

Example 12

Synthesis of(10S,17S,21S)-10-(4-fluorobenzyl)-8,11,19-trioxo-1-((4-((1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,9,12,18,20-pentaazatricosane-17,21,23-tricarboxylicacid (MIP-1546) was carried out as illustrated in Scheme 6 above.

[MS (ESI)]: (M+H)⁺=1150.

Example 13

Synthesis of(10S,17S,21S)-10-(4-fluorobenzyl)-8,11,19-trioxo-1-((4-((1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,9,12,18,20-pentaazatricosane-17,21,23-tricarboxylateLu complex (Lu-MIP-1546) was carried out as illustrated in Scheme 6above

[MS (ESI)]: (M+H)⁺=1321.

Example 14 Synthesis of(10S,17S,21S)-10-(naphthalen-2-ylmethyl)-8,11,19-trioxo-1-((4-((1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,9,12,18,20-pentaazatricosane-17,21,23-tricarboxylicacid (MIP-1545)

[MS (ESI)]: (M+H)⁺=1182.

Example 15 Synthesis of(10S,17S,21S)-10-(naphthalen-2-ylmethyl)-8,11,19-trioxo-1-((4-((1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,9,12,18,20-pentaazatricosane-17,21,23-tricarboxylateLu complex (Lu-MIP-1545)

[MS (ESI)]: (M+H)⁺=1352.

Example 16

Synthesis of(10S,13S,20S,24S)-13-(2-carboxyethyl)-10-(4-fluorobenzyl)-8,11,14,22-tetraoxo-1-((4-((1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,9,12,15,21,23-hexaazahexacosane-20,24,26-tricarboxylicacid (MIP-1550) was carried out as illustrated in Scheme 7 above.

[MS (ESI)]: (M+H)⁺=1279.

Example 17

Synthesis of(10S,13S,20S,24S)-13-(2-carboxyethyl)-10-(4-fluorobenzyl)-8,11,14,22-tetraoxo-1-((4-((1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,9,12,15,21,23-hexaazahexacosane-20,24,26-tricarboxylateLu complex (Lu-MIP-1550) was carried out as illustrated in Scheme 7above

[MS (ESI)]: (M+H)⁺=1450.

Example 18 Synthesis of(11S,16S,20S)-11-(2-carboxyethyl)-10,13,18-trioxo-1-((4-((1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,9,12,17,19-pentaazadocosane-16,20,22-tricarboxylicacid (MIP-1519)

[MS (ESI)]: (M+H)⁺=1100.

Example 19 Synthesis of(11S,16S,20S)-11-(2-carboxyethyl)-10,13,18-trioxo-1-((4-((1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,9,12,17,19-pentaazadocosane-16,20,22-tricarboxylateLu complex (Lu-MIP-1519)

[MS (ESI)]: (M+H)⁺=1271.

Example 20 Synthesis of(13S,17S)-10,15-dioxo-1-((4-((1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,9,14,16-tetraazanonadecane-13,17,19-tricarboxylicacid (MIP-1526)

[MS (ESI)]: (M+H)⁺=970.

Example 21 Synthesis of(13S,17S)-10,15-dioxo-1-((4-((1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,9,14,16-tetraazanonadecane-13,17,19-tricarboxylateLu complex (Lu-MIP-1526)

[MS (ESI)]: (M+H)⁺=1142.

Example 22 Synthesis of(11S,16S,20S)-11-benzyl-10,13,18-trioxo-1-((4-((1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,9,12,17,19-pentaazadocosane-16,20,22-tricarboxylicacid (MIP-1548)

[MS (ESI)]: (M+H)⁺=1118.

Example 23 Synthesis of(11S,16S,20S)-11-benzyl-10,13,18-trioxo-1-((4-(1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecan-2-yl)methyl)phenyl)amino)-1-thioxo-2,9,12,17,19-pentaazadocosane-16,20,22-tricarboxylateLu complex (Lu-MIP-1548)

[MS (ESI)]: (M+H)⁺=1289.

Synthetic protocols described above will be used to synthesize Formula Iand Formula II compounds in which the chelator is a moiety selected from

Formula I or Formula II compounds thus obtained may then be complexedwith an appropriate radionuclide to give a radiopharmaceutical that issuitable for diagnostic imaging or for use as a therapeutic for treatingcell proliferative diseases. Illustrative compounds having the aboveillustrated chelator groups include but are not limited to:

EQUIVALENTS

While certain embodiments have been illustrated and described, it shouldbe understood that changes and modifications can be made therein inaccordance with ordinary skill in the art without departing from thetechnology in its broader aspects as defined in the following claims.

The present disclosure is not to be limited in terms of the particularembodiments described in this application. Many modifications andvariations can be made without departing from its spirit and scope, aswill be apparent to those skilled in the art. Functionally equivalentmethods and compositions within the scope of the disclosure, in additionto those enumerated herein, will be apparent to those skilled in the artfrom the foregoing descriptions. Such modifications and variations areintended to fall within the scope of the appended claims. The presentdisclosure is to be limited only by the terms of the appended claims,along with the full scope of equivalents to which such claims areentitled. It is to be understood that this disclosure is not limited toparticular methods, reagents, compounds compositions or biologicalsystems, which can of course vary. It is also to be understood that theterminology used herein is for the purpose of describing particularembodiments only, and is not intended to be limiting.

In addition, where features or aspects of the disclosure are describedin terms of Markush groups, those skilled in the art will recognize thatthe disclosure is also thereby described in terms of any individualmember or subgroup of members of the Markush group.

As will be understood by one skilled in the art, for any and allpurposes, particularly in terms of providing a written description, allranges disclosed herein also encompass any and all possible subrangesand combinations of subranges thereof. Any listed range can be easilyrecognized as sufficiently describing and enabling the same range beingbroken down into at least equal halves, thirds, quarters, fifths,tenths, etc. As a non-limiting example, each range discussed herein canbe readily broken down into a lower third, middle third and upper third,etc. As will also be understood by one skilled in the art all languagesuch as “up to,” “at least,” “greater than,” “less than,” and the like,include the number recited and refer to ranges which can be subsequentlybroken down into subranges as discussed above. Finally, as will beunderstood by one skilled in the art, a range includes each individualmember, including the first and last number listed for the range.

All publications, patent applications, issued patents, and otherdocuments referred to in this specification are herein incorporated byreference as if each individual publication, patent application, issuedpatent, or other document was specifically and individually indicated tobe incorporated by reference in its entirety. Definitions that arecontained in text incorporated by reference are excluded to the extentthat they contradict definitions in this disclosure.

Other embodiments are set forth in the following claims.

What is claimed is:
 1. A compound represented by formula I

wherein: X and Y are each independently (CHR¹)_(m) or C(O); W is H or—(CH₂)_(p)—U; L is —C(O)—(C₁-C₁₀)alkylene,—[C(O)—(CH(Z)_(d))—NH]_(j)NR²R³, —C(O)—(CHR¹)—(CH₂)_(p)—U—,—(C₅-C₁₄)aryl-(C₁-C₁₀)alkylene, R⁶O-benzylene,—(C₅-C₁₄)heteroaryl-(C₁-C₁₀)alkylene,—C(O)—[(CH₂)_(p)—V]_(n)—(CH₂)_(q)—C(O)—U or[C(O)—CH(Z)_(d)—NH]_(t)—C(O)—(CHR¹)_(m)—(CH₂)_(p)—U; T is selected fromthe group consisting of: H, —(C₁-C₁₀)alkylene, RC(O)—(C₁-C₁₀)alkylene,NR²R³—(C₁-C₁₀)alkylene, —(C₅-C₁₄)heteroaryl-(C₁-C₁₀)alkylene and—(C₅-C₁₄)aryl-(C₁-C₁₀)alkylene; U is selected from the group consistingof: —OR, —COR and —NR⁴R⁵; V is selected from the group consisting ofU—NH—, —NR²— and —NR²R³; Z is —(CH₂)_(p)—COOH or —(CH₂)_(p)—NR²R³; R,R^(a) and R^(b) are each independently —H, —OH, —(C₁-C₁₀)alkyl,—O(C₁-C₁₀)alkyl, or NHR²; R¹ and R′″ are each independently —H or —NH₂;R², R³, R⁴ and R⁵ are each independently H, bond, (C₁-C₁₀)alkylene, F,Cl, Br, I, C(O), C(S), —C(S)—NH-benzyl-, —C(O)—NH-benzyl-,—C(O)—(C₁-C₁₀)alkylene, —(CH₂)_(p)—NH—C(O)—(CH₂)_(p)—,—(CH₂—CH₂)_(t)—NH—C(O)—(CH₂)_(p)—, —(CH₂)_(p)—COR,—(CH₂)_(p)—C(O)NH—C[(CH₂)_(p)—COR]₃, —C[(CH₂)_(p)—COR]₃, or—(CH₂)_(p)—(C₅-C₁₄)heteroaryl; R⁶ is—O(CH₂)_(p)—(C₅-C₁₄)heteroaryl-(CH₂)_(p)—U;

d, j, k, m, n, p and t are each independently 0, 1, 2, 3, 4, 5, or 6;and with the proviso that where W is —(CH₂)₅— or —CH(NH₂)—(CH₂)₄—, L isnot a —C(O)CH₂—.
 2. The compound of claim 1, wherein X is (CHR¹)_(m), Yis C(O), W is hydrogen and k is
 5. 3. The compound of claim 1, wherein Lis —C(O)CH₂— and T is hydrogen.
 4. The compound of claim 1, wherein R¹is hydrogen and m is
 2. 5. The compound of claim 1, wherein L is—C(O)—[(CH₂)_(p)—V]_(n)—(CH₂)_(q)—C(O)—U or —C(O)—(C₁-C₁₀)alkylene. 6.The compound of claim 5, wherein L is —C(O)methylene.
 7. The compound ofclaim 5, wherein L is —C(O)—[(CH₂)_(p)—V]_(n)—(CH₂)_(q)—C(O)—U and T ishydrogen.
 8. The compound of claim 7, wherein V is NR², n is 2 and qis
 1. 9. The compound of claim 7, wherein U is NR²R³.
 10. The compoundof claim 9, wherein R² is hydrogen and R³ is —(CH₂)₂—NH—C(O)—(CH₂)—. 11.The compound of claim 1, wherein L is OR⁶-benzylene and T is—(C₅-C₁₄)heteroaryl-(C₁-C₁₀)alkylene.
 12. The compound of claim 11,wherein the heteroaryl is an imidazole, further substituted with thegroup —(C₁-C₁₀)alkylene-C(O)—U.
 13. The compound of claim 11, wherein Tis selected from the group consisting of


14. The compound of claim 1, wherein T is.


15. The compound of claim 14, wherein each R′″ is independently


16. The compound of claim 4, wherein W is —(CH₂)—COOH, k is 1, L is—[C(O)—(CH(Z)_(d))—NH]_(j)—NR²R³ and T is hydrogen.
 17. The compound ofclaim 16, wherein R² is hydrogen, R³ is —C(O)CH₂— and j is
 4. 18. Thecompound of claim 4, wherein W and T are hydrogen, k is 5, and L is[C(O)—CH(Z)_(d)—NH]_(t)—C(O)—(CHR¹)_(m)—(CH₂)_(p)—U.
 19. The compound ofclaim 18, wherein Z is —(CH₂)₄—NR²R³ and U is —NR⁴R⁵.
 20. The compoundof claim 18, wherein m and t are 1, p is 4 and R¹ is —NH₂.
 21. Thecompound of claim 19, wherein R⁴ is hydrogen and R⁵ is C(O)methylene.22. The compound of claim 19, wherein R² and R³ are each independently—(CH₂)_(p)—(C₅-C₁₄)heteroaryl.
 23. The compound of claim 18, wherein pis 1 and the heteroaryl is an imidazole, further substituted with thegroup —(C₁-C₁₀)alkylene-C(O)—U.
 24. The compound of claim 1, which is:

or a pharmaceutically acceptable salt, or ester thereof.
 25. A metalcomplex comprising a radionuclide and the compound of claim
 1. 26. Themetal complex of claim 25, wherein the radionuclide is selected from thegroup consisting of ¹¹¹In, ⁹⁰Y, ⁶⁸Ga, ⁶⁴Cu ¹⁵³Gd, ¹⁵⁵Gd, ¹⁵⁷Gd, ¹⁵⁷Feand ¹⁷⁷Lu.
 27. The metal complex of claim 25, which is:

or a pharmaceutically acceptable salt thereof; wherein M is ¹¹¹In, ⁹⁰Y,⁶⁸Ga, ⁶⁴Cu, or ¹⁷⁷Lu.
 28. A pharmaceutical composition comprising thecompound of claim 1, or a pharmaceutically acceptable salt or esterthereof; and a pharmaceutically acceptable carrier.
 29. A pharmaceuticalcomposition comprising the metal complex of claim 25, or apharmaceutically acceptable salt or ester thereof; and apharmaceutically acceptable carrier.